Transatlantic Slave Trade
From the 1520s to the 1860s an estimated 11 to 12 million African men, women, and children were forcibly embarked on European vessels for a life of slavery in the Western Hemisphere. Many more Africans were captured or purchased in the interior of the continent but a large number died before reaching the coast. About 9 to 10 million Africans survived the Atlantic crossing to be purchased by planters and traders in the New World, where they worked principally as slave laborers in plantation economies requiring a large workforce. African peoples were transported from numerous coastal outlets from the Senegal River in West Africa and hundreds of trading sites along the coast as far south as Benguela (Angola), and from ports in Mozambique in southeast Africa. In the New World slaves were sold in markets as far north as New England and as far south as present-day Argentina.
The Early History of European Trade with Africa
The marketing of people in the interior of Africa predates European contact with West Africa. A Trans-Saharan slave trade developed from the tenth to fourteenth century which featured the buying and selling of African captives in Islamic markets such as the area around present-day Sudan. A majority of those enslaved were females, who were purchased to work as servants, agricultural laborers, or concubines. Some captives were also shipped north across the deserts of northwest Africa to the Mediterranean coast. There, in slave markets such as Ceuta (Morocco), Africans were purchased to work as servants or laborers in Spain, Portugal, and other countries.
By the mid-1400s, Portuguese ship captains had learned how to navigate the waters along the west coast of Africa and began to trade directly with slave suppliers who built small trading posts, or "factories," on the coast. European shippers were thus able to circumvent the trans-Saharan caravan slave trade. The slave trade to Europe began to decrease in the late 1400s with the development of sugar plantations in the Atlantic islands of Madeira and São Tomé. These two islands, located off West Africa and in the Gulf of Guinea, became leading centers of world sugar production and plantation slavery from the mid-1400s to the mid-1500s. Portuguese merchants dominated this early trade.
Much of the earliest European trade with West Africa, however, was in gold, not people. Europeans did not have the power to overcome African states before the late nineteenth century, and gold production, centered in Akan gold fields in the backcountry of present-day Ghana, remained in African hands. Europeans called this region the Gold Coast. Agreements between African and European elites and rivalries for the African gold trade resulted in the construction of dozens of trading forts, or stone castles, along a 161 km (100 mi) coastal stretch of Ghana. Several of these forts survive, have been repaired by the government of Ghana, and are tourist attractions today. It was not until the late seventeenth century that the value of European goods traded for African people surpassed the value of goods exchanged for gold. Over time, these gold forts became slave forts, where hundreds of Africans were confined in prisons awaiting sale and shipment.
The Slave Trade and Development of Plantations in the Americas
Christopher Columbus's "discovery" of the New World in 1492 marked the beginning of a transatlantic trading system. Via the slave trade, Africans played a leading role in the creation and evolution of this large and long-lasting "Atlantic system." Spanish adventurers arrived in the Americas hoping to trade for riches but soon enslaved the Native American peoples in their search for gold and silver. Disease, malnutrition, and Spanish atrocities led to the deaths of millions of the Indians of the Americas. By the 1520s the depopulation of the region prompted the Spanish government to look for alternative sources of labor. Officials contracted with Portuguese merchants to deliver Africans to Spanish territories in the New World. The first transatlantic slave voyages from Africa to the Americas occurred in the early 1520s on Portuguese vessels sailing from West Africa to the large Caribbean island of Hispaniola, the earliest European name for present-day Haiti and the Dominican Republic.
The transatlantic slave trade increased in the mid-1500s, when the Spanish began to use African slave labor alongside Native Americans to mine silver in Peru. Slave ships sailed from Africa to Colombia and Panama, and African captives then were transported overland to the Pacific coast of South America. Until the early 1600s, most Africans enslaved in the Americas worked in Peruvian or Mexican mines. The 1570s marked the development of sugar plantations in Brazil, a Portuguese colony, where merchants adopted production techniques pioneered in Madeira and São Tomé. By the 1620s African labor had replaced Indian labor on Brazilian sugar plantations.
The development of an export-based plantation complex in North America and the Caribbean, areas neglected by the Spanish and Portuguese, awaited the arrival of the British, French, and Dutch in the early 1600s. In the initial development of the British colonies Virginia and Barbados (1630s-1640s), Jamaica (1660s), and South Carolina (1690s) and the French colonies Saint-Domingue (present-day Haiti), Martinique, and Guadeloupe (1660s-1680s), most laborers on the plantations were young European males who agreed to work for three to five years in return for free oceanic passage and food and housing in the Americas. These workers were called indentured laborers. By the later seventeenth and early eighteenth centuries, tobacco, sugar, indigo (used to make blue dye), and rice plantations switched from European indentured labor to African slave labor. By the mid-1700s, Brazil, Saint-Domingue, and Jamaica were the three largest slave colonies in the Americas. By the 1830s, Cuba emerged as the principal Caribbean plantation colony. Throughout the history of the transatlantic slave trade, however, more Africans arrived as slaves in Brazil than in any other colony.
Dutch merchants did not develop extensive plantation colonies in the New World but they became large slave traders in the mid-seventeenth century. The small Dutch Republic was among the first European nations to develop modern commerce, and merchants there had access to shipping, port facilities, and banking credit. Dutch traders occupied several trading castles on the African coast, the most important of which was Elmina (in Ghana), a fort they captured from the Portuguese and rebuilt. The Dutch wrested control of the transatlantic slave trade from the Portuguese in the 1630s, but by the 1640s they faced increasing competition from French and British traders. By the 1680s, a variety of nations, private trading companies, and merchant-adventurers sent slave ships to Africa: merchants from Denmark, Sweden, and the German states also organized slave voyages. Throughout the eighteenth century — the height of the transatlantic slave trade — the largest traders were the British, Portuguese, and French.
The Organization of Slave Voyages
Transatlantic slave voyages were complex commercial endeavors. Voyages based in Europe sailed a route linking Europe, Africa, and the Americas. Contemporaries saw this as a profitable "triangular trade." European goods were exchanged for slaves in Africa; slaves were sold in the Americas for plantation produce, such as sugar, which was transported back to Europe in the holds of slave vessels. Trade cargoes organized in Europe cost several millions of dollars in today's money, and the average value of outward cargoes was greater than most overseas trades. Cargoes typically included India cotton textiles, cowrie shells from the Indian Ocean, Brazilian tobacco, glassware from Italy, brandies and spirits from France, Spain, and Portugal, Irish linen and beef, and a range of British and European manufactures. At one time, historians argued that cheap trinkets were sold for African slaves, but recent research shows that African traders demanded a large variety of goods — in particular, textiles — and that over time more and more European goods were exchanged for African captives as slave prices increased.
Slave vessels sailed from Europe with large crews, including surgeons, carpenters, coopers (barrel-workers), cooks (some of whom were of African descent), sailors (who apprenticed to sea at a young age), and others hired to guard slaves on the African coast and on the Middle Passage, where threats of rebellion and insurrection were constant. Slave vessels ranged in size from small sloops and schooners to larger ships measuring hundreds of tons. Some of these larger three-masted ships had three decks and were more than 30 m (100 ft) in length and 12 m (40 ft) in breadth. Few slave vessels were constructed specifically for the trade. By the mid-1800s, some slave vessels were built of wood and iron and powered by steam; these vessels sailed up rivers such as the Congo and sometimes purchased over 1000 African slaves. Smaller, shallower-built slave vessels traded in the the Gambia, Senegal, and Sierra Leone Rivers in West Africa and along the Windward Coast (present-day Liberia). Because the Gold Coast lacks large river outlets or safe anchorages, slave vessels anchored several miles offshore, where they were met by large trading canoes. In the major slaving-trading sites of Whydah (in modern-day Republic of Benin), Bonny, and Old Calabar (in present-day Nigeria), slave vessels anchored in lagoons or bays close to African villages and small towns. Large slave ships also traded in rivers and bays on the Angolan coast and in Mozambique in southeast Africa. In comparison with other Atlantic traders, however, most slave vessels were small, relatively inexpensive vessels, and were rigged for speed. Most slave vessels made only a few voyages to Africa and transported between 250 and 300 slaves.
When a slave vessel arrived on the African coast, trade was "broken" by a variety of customs payments to local African rulers or merchants. Captains also paid fees to African sailors who piloted slave vessels across sandbars to anchorages. The captains' first tasks included purchasing (or gathering) wood, water, and other provisions from shore. The wood was brought on board for fuel and for the carpenter to build a large box-shaped barricade placed above the upper deck. Slaves were led through a small door on the barricade to the hatches and decks below. The barricade was a security precaution and it kept Africans from seeing their homeland, according to the testimony of some slave traders. In many parts of Africa a "trust trade" developed as European captains advanced trading goods to African slave dealers with the promise of future slave deliveries. These dealers often were small-scale traders who built factories with connecting warehouses to store goods and outdoor, fenced "pens" or enclosed "barracoons" to confine slaves. Sometimes sons or daughters of the local chiefs were given temporarily to the slave-ship captains as a form of credit known as pawnship. When a captain kidnapped "pawns" (which occurred infrequently), the local African ruler would cut off all slave trading from the region. Often the captain and crew of the next vessel from that port would be killed or taken hostage as retribution.
There was a complex system of exchange between European, Afro-European, and African agents. Bundles, or "assortments," of European trading goods were traded for a specified number of African units of exchange which then were exchanged for a specified number of slaves. The units of exchange varied regionally in Africa and included European iron bars, cowrie shells from the Indian Ocean, Italian beads, blue-dyed Indian textiles, or Brazilian gold. In the late eighteenth century, an assortment of European textiles, firearms, and alcohol would, for example, be equivalent to 12 ounces of gold along the Gold Coast; 12 ounces of gold would be the "price" of an adult male African slave. The profitability of a slave voyage often depended upon the ability of a merchant or captain to "assort" his trading goods to meet short-term African demand. There were many coastal agents who traded with slave-ship captains who did not have a properly "assorted" cargo. Many of these agents, particularly those who lived on the coast from present-day Guinea-Bissau southeast to Liberia, were of Afro-European descent.
Slave vessels remained on the coast of Africa usually from four to six months, depending on the trading location, availability of slaves and provisions, and the health of slaves and crew. Some provisions for the coastal stay and Middle Passage were loaded in Europe, but often captains purchased rice, beans, fish,and yams on the coast of Africa. Some small vessels loaded slave cargoes in a few weeks from small wooden factories or the larger stone trading forts. At some trading sites, such as late-eighteenth-century Bonny (in Nigeria), African merchants created sophisticated slave-trading road and river networks from the interior to the coast. Slave supplies were regular, and sometimes 10 to 20 slaves would be purchased and loaded on board ship per day. The supply of slaves from the interior depended largely on political warfare (since many male slaves were war prisoners) and ecological conditions. During times of drought or famine, slave supplies increased as people who could not be supported by villages were sold for money or provisions. Slave raiding also occurred, though it is likely that a smaller percentage of Africans entered slavery through village raids. Often, however, the distinction between wars and slave raids was blurred. Within a few weeks of departure from the coast, captains purchased final supplies of food, water, and wood for the Middle Passage.
The Middle Passage
From a European geographic perspective, the Middle Passage was the second, or middle, leg of the triangular voyage between Europe, Africa, and the Americas. This was the notorious cross-Atlantic journey where hundreds of slaves were confined in irons below deck in crowded, hot, unsanitary, and inhumane conditions. The chance of insurrection was greatest during the first few weeks of the Middle Passage. During this time, most slaves were kept below deck, naked or only partially clothed with a loincloth, shackled in pairs, right leg to left leg. Nonetheless, slaves sometimes broke free of their chains and attacked the crew with a variety of tools and small weapons. Slave vessels were equipped with guns and cannons which were placed on the raised quarterdeck to fire down upon slaves escaping through the hatches. Occasionally, Africans in war canoes attacked slave vessels from shore. Researchers have documented more than 450 slave insurrections or shore-based attacks, and there were undoubtedly many more that went unrecorded. Occasionally, some captives would regain the shores of Africa. More often the crew regained control of the ship or Africans were reenslaved upon reaching shore. Uprisings were extremely violent, and sometimes many slaves and most crew were killed. When African captives gained control of the ship, they kept a few crew alive to navigate the vessel.
Ships' officers confined the men, women, boys, and girls in separate compartments. Slave vessels were fitted with numerous wooden platforms between decks to allow captains to pack in greater numbers of captives. As the between-deck space was generally from 1.2 m (4 ft) to 1.8 m (6 ft), platforms reduced the head room for captives to only a few feet. All slaves suffered from numerous scrapes and bruises from lying on these bare planks. Captains claimed that when safely away from shore, slaves were given greater freedom of movement. Women and children, some claimed, were never shackled and were allowed to roam above deck with minimal supervision. Recently, however, archaeologists discovered many small-sized leg irons from the wreck of the slave ship Henrietta Marie (c. 1700) off Florida. Women may have been separated from male slaves and given greater freedom of movement to increase the crews' sexual exploitation of them.
Cooks prepared meals of fish, beans, or yams in large copper vats below deck. Surgeons sometimes assisted in the preparation and distribution of food. Slaves were given food at mid-morning and late afternoon in small bowls (or "pannikins"). Weather permitting, groups of African captives were exercised above deck (in their leg irons) in an attempt to offset the debilitating effects of the Middle Passage. Officers, usually boatswains, mates, and surgeons, were armed with whips such as the cat-o'-nine-tails and forced the African captives to dance. The crew's power was enforced through such torture devices as thumbscrews and iron collars. There were several tubs in each compartment below deck in which slaves could relieve themselves, though hindered by being shackled in pairs. Mates generally had the job of cleaning the slave compartments below deck, which each day would be covered with excrement, blood, and filth. Some captains frequently ordered the rooms washed and dried with fire pans, though sometimes the filth was simply scraped off the decks. To counteract the stench, which was thought to promote sickness, slave vessels were fumigated with vinegars, berries, limes, tars, and turpentines.
By any measurement, mortality rates of both slaves and crew were extraordinarily high on the Atlantic crossing. The crowded, unsanitary conditions below deck were an ideal disease environment for outbreaks of dysentery, the disease from which many slaves died. In addition to gastrointestinal diseases, Africans also died from dehydration, smallpox, or measles. Slaves who resisted captivity sometimes died from flogging or other forms of punishment. Some slaves committed suicide by jumping overboard or by starving or hanging themselves. The resistance to eating was so common that vessels carried metal devices to force-feed slaves. Sailors died mostly from malarial and yellow fevers, to which African-born peoples had some acquired immunities. Early in transatlantic slave trade about 15 to 20 percent of African captives died on the Passage. By the later eighteenth century, about 5 to 10 percent died, a reduction perhaps caused by improvements in hygiene and sanitation. Slave mortality rose in the nineteenth century during years when the British navy tried to enforce an international ban on the slave trade. About 15 to 20 percent of the crew died on the triangular voyage and sailors died at rates often greater than for all other overseas trades combined. Slave mortality usually increased during the last stages of a particularly long passage when there were shortages of food and water.
The Atlantic crossing lasted three to five weeks from West African trading sites such as the Gambia, Senegal, and Sierra Leone Rivers. Near the equator, in regions such as the Bights of Benin and Biafra (near present-day Nigeria), the voyage to the Americas took several months. A few French ships transported slaves from Mozambique or Madagascar to the Mascarene Islands in the Indian Ocean and then returned to France via Saint-Domingue in the West Indies, where additional cargoes of captives from southeast Africa were disembarked. These voyages — via the Indian Ocean — were the most complex in the transatlantic slave trade and took several years to complete. In the nineteenth century, passage time in the trade fell dramatically due to advances in shipbuilding and speed.
The Marketing of Enslaved Africans in the Americas
Upon arriving in the Americas, African captives who survived the Atlantic crossing were "refreshed" with water and colonial provisions (such as citrus fruit) and were shaved and cleaned. Ointments (to hide scars from diseases such as yaws) and oils were applied on their skin in preparation for sale. Agents placed advertisements in colonial gazettes and in taverns for the sale of African labor, which usually began a few weeks after arrival. Many sales occurred on ship deck; other sales took place on wharves or in agents' houses or slave pens. Some planters contracted with merchants to purchase a preset number of slaves. Many slaves were sold by "scramble" or by auction. During the scramble, planters or their representatives placed ropes or handkerchiefs around groups of slaves whom they wanted to purchase. During auctions, the highest-valued slaves, often adult men, were sold first sold; then, over several weeks or even months, less-valued slaves were sold. The last slaves sold were often old, sick, or debilitated Africans. Termed "refuse slaves," they usually were purchased by doctors or poor colonists. In some sales "prime" slaves were sold by scramble and "refuse" slaves were sold at public auction. Occasionally slave cargoes included family members or relatives, but separation during sale was almost inevitable. Cargoes also usually comprised Africans from different ethnic groups, as can be noted through ethnic scarification. Some planters purchased slaves from a variety of ethnic backgrounds as part of labor control; other planters purchased Africans from the same areas of Africa to maintain workforce unity.
Ship captains and colonial agents sold slave cargoes to planters for bills of exchange, which often were resold for return cargoes of plantation produce. Slave vessels were not specialist "West Indiamen" (large produce vessels built for storage capacity), however, and transported only a fraction of the produce of the Americas back to Europe. By the mid-eighteenth century, many slave vessels began returning to Europe with the planters' bills of exchange and only small cargoes of plantation produce. Thus, though many slave vessels sailed on triangular voyages over the course of about a year, some did not carry on a triangular trade. An important exception to the concept of a triangular trade was the large Brazil-to-Angola shuttle trade, which dates from the 1680s. By the nineteenth century, small Brazilian vessels, built for speed, sometimes made three or four slave voyages per year in this direct trade.
The Abolition of The Transatlantic Slave Trade
After centuries of broad acceptance, in the mid-eighteenth century some religious leaders began to question the morality of enslaving and owning humans. They began a campaign, termed the abolition movement, to end slavery. Faced with overwhelming opposition of colonial and business groups, the "abolitionists" realized that the first step toward ending slavery would be to end the transatlantic slave trade. Attacking the British slave trade was vital: the British were the largest slave traders by the mid-1700s. The abolition of the British trade was a 20-year process: Parliament first regulated the trade, limiting the number of slaves British vessels could carry from Africa, then closed a number of colonies to slave imports, and then in 1807 abolished the trade itself. The size of the British trade highlights the important abolitionist triumph: during the previous decade, 150 British slave vessels had sailed per year for the African coast to purchase more than 40,000 African men, women, and children.
Five years earlier, in 1803, the small Danish slave trade ended by a government order enacted in 1792. The United States slave trade — centered in Rhode Island — ended in 1807, the first year Congress could address the question of abolition, as agreed to by the compromise between Northern and Southern states writing the Constitution in 1787. The French slave trade ended temporarily in the early 1790s after the slave revolution in the largest French colony, Saint-Domingue, removed the principal French slave market, and then the French government abolished slavery throughout French colonies in 1793-1794. With the ending of the Napoleonic Wars in 1814-1815, British diplomats attempted to end the international slave trade. The Dutch trade, which largely ended during the late-eighteenth-century warfare with France, was abolished by decree in 1814. The restored, conservative French monarchy, however, did not agree to end French participation in the slave trade. French vessels continued to ship slaves to Martinique, Guadeloupe, and Cayenne (in modern-day French Guiana), and the French government did not abolish slavery in French colonies until 1848. The French trade, however, had effectively ended by 1831 after a political revolution in the country.
After 1815 the transatlantic slave trade centered on the expanding sugar and coffee colonies of Brazil and Cuba. British diplomats continued to negotiate for a total ban on the slave trade, and British naval ships cruised the African coast to capture illegal slave ships. By the 1820s most slave voyages originated from the West Indies or Brazil. To avoid British confiscation, "flags of convenience" were carried on board. Many European or American-owned slave vessels sailed under Spanish-Cuban registration. British naval pressure and changing Brazilian attitudes about the slave trade led to government measures which effectively ended the trade by the early 1850s. The remaining market of Cuba experienced a short-term increase in slave imports from 1853 to 1860 as slave and sugar prices rose. Prices fell in the 1860s, and by 1867 British, Spanish, and U.S. authorities were able to end the direct slave trade from Africa to Cuba.
Long-term Trends and Impacts of the Transatlantic Slave Trade
The Transatlantic Slave Trade first centered on West Africa, the Gold Coast, Hispaniola, Mexico, and Peru. Most of the slaves shipped from Africa during the period of 1520 to 1570 were male and worked in Spanish American mines. Over time, an increasing number of Africans transported across the Atlantic left from outlets in Nigeria or Angola, and more and more would work in Brazil and the British and French Caribbean colonies. Two of every five Africans arrived in Brazil; in the nineteenth century, perhaps four of five African slaves were destined for Brazilian plantations. The British and French Caribbean colonies each accounted for about one-fifth of the total trade. In the eighteenth century, Saint-Domingue and Jamaica were the largest plantation economies in the West Indies and the principal destinations for most African captives on French and British slave vessels. Slave imports, sometimes numbering 20,000 men, women, and children per year, replaced populations which did not increase by natural rates. The slave trade to what is now the United States constituted only about 7 percent of the total trade. This number may seem surprising, given the fact that the U.S. South developed one of the largest slave societies in the nineteenth century. But the development of a cotton plantation economy in the first half of the 1800s occurred after the abolition of the slave trade. In contrast to many plantation regimes, slave populations increased markedly within the United States. Most African captives arrived in British North America and the United States from the Congo River area, Senegambia, the Bight of Biafra, the Gold Coast, and the Sierra Leone region. In the four years prior to abolition, 5000 to 7000 slaves landed annually in Charleston. This was the height of the transatlantic slave trade to the United States.
During the history of the transatlantic slave trade, conditions of slave supply in Africa, the demand of planters for slaves of certain gender, ages, or broadly understood African "ethnicities," and European commercial rivalries shaped the movement of slaves from African to American markets. Brazil received perhaps two-thirds of African captives from Angola (with principal ports of Luanda and Benguela, under Portuguese control), one-quarter from the Bight of Benin, called also the Slave Coast (near present-day Dahomey), and smaller numbers from Mozambique and the region around the Bijagós Islands off West Africa. French slave vessels delivered African labor to Saint-Domingue mostly from Angola, the Bight of Benin, the Senegal River area, Calabar, and Gabon. French merchants had few slaving contacts on the Windward Coast (near Liberia) or the Gold Coast. Most African captives arrived in British North America and the United States from the Congo River area, Senegambia, the Bight of Biafra, the Gold Coast, and the Sierra Leone region. The British Caribbean drew laborers from a wide range of African coastal outlets, though by the later eighteenth century the Bight of Biafra (Nigeria) and Angola began to predominate. Jamaica had particularly close commercial links with the Bight of Biafra and the Gold Coast. The Cuban plantation economy developed from the 1760s to 1860s with the most "diversified" African slave labor force. Cuba contracted slave shipments from various European merchants, each with their own African trading contacts. By the late eighteenth century, the Spanish government opened the Havana market to flags of all nations. No single African region supplied more than one-third of Cuban slave imports.
Over time there were changes in the stream of men, women, and children who entered transatlantic slaving networks. Throughout most years of the trade, the Bight of Biafra supplied the most women captives to coastal traders. Disproportionate numbers of adult male slaves were shipped from the Gambia and Senegal Rivers. Often more than one in five Africans transported from the Windward Coast were children. By the nineteenth century greater numbers of children were forced into the trade from almost all regions in Africa. The proportion of men also increased. Scholars have yet to explain fully these age and gender variations between African regions and over time.
Why was African labor forcibly transported thousands of miles to the Americas to work in the economies of the New World? In the past, historians have argued that Africans were a low-cost labor alternative to scarce Indian labor (scarce, because most Indian populations were destroyed by disease) or expensive European labor. African skin color also identified plantation slaves from other colonial workers, which facilitated planter control. Further, there were declining numbers of European men who were willing to work as plantation laborers because job opportunities increased in Europe; there was greater competition among European slave shippers, which increased the regularity and lowered the price of Africans in the Americas; and there were entrenched racist attitudes that justified European dominance over peoples from Africa. Others have argued that African peoples had a biological advantage over European laborers in the Americas. With some acquired immunities to tropical diseases such as yellow fever and malaria, Africans proved better able to survive the disease environments of the South Atlantic and Caribbean. Recent scholarship has pointed out that the organization of the European slave trade to Africa was a costly endeavor and that it would in fact have been less expensive to ship European convicts to work the plantations of the Americas. In this view, the organization of a European slave trade to the African coast has less to do with economics and more to do with developing European imperial ambitions to enslave and dominate those people defined as outsiders.
Scholars have also disagreed over the size of this forced Atlantic migration. To many, the size of the transatlantic slave trade represents the scale of European destructive impact on Africa. We may never know the extent of the slave trade in the interior of Africa, or the numbers of slaves who died en route to the coastal barracoons. As an Atlantic maritime enterprise, however, the transatlantic slave trade is well documented: European governments taxed vessels clearing and entering customs, and many newspapers and colonial gazettes survive, as do general shipping documents such as muster rolls and ship registers. Moreover, slave vessels often were at sea for more than a year and were on the coast of Africa and harbors in the Americas for several months. These vessels were noticed. The large British trade is particularly well documented, and British navy officials kept extensive records of the illegal slave trade of the nineteenth century. Studies based on these numerous shipping and government documents, including Harvard University's W. E. B. Du Bois Institute's database of 27,500 slave voyages, compiled in 1993-1997, have supported an estimate of about 11 to 12 million slave exports and 9 to 10 million slave imports into the Americas. Importantly, these totals represent more than 60 percent of all Atlantic migrants before the nineteenth century. By the 1820s, after the abolition of the British, U.S., and Dutch slave trades, African migrants crossing the Atlantic still outnumbered all other European migrant groups. Also, African women outnumbered European female migrants by a ratio of more than five to one. Only by the 1840s would the number of migrants voluntarily leaving Europe for the Americas exceed the number of enslaved migrants from Africa.
What was the impact of this massive population shift? Scholars have argued that the transatlantic slave trade was an extremely profitable business that created pools of investment capital linked to industrialization in areas of Europe and North America. Extraordinary profits were achieved, however, on only a handful of voyages per year. Slave trading was extremely competitive and risky. In a broader view, the transatlantic slave trade provided African labor necessary to develop the plantation economies of the Americas. Most colonies specialized in single crops, such as sugar, and were dependent largely on Europe or North America for supplies and provisions. Thus within the Atlantic system regional, specialized economies, linked through maritime trade, developed. Such trade specialization likely stimulated economic growth and increased prosperity for those living in Europe and the Americas.
By the eighteenth century, standards of living had increased among many of the middle and lower classes in Europe and British North America. This in turn increased consumer demand for plantation luxuries such as sugar, tobacco, coffee, and spices. In response to this increased demand, planters in the Americas enlarged their estates, purchasing more labor from Africa to increase production. This expansion of the transatlantic slave trade in the eighteenth century, therefore, is a function of the income of European consumers and their demand for plantation goods. Without the forced labor of peoples of African descent, European consumers would have paid much higher prices for a wide range of subtropical produce. Economic growth in the North Atlantic thus stimulated the slave trade and the latter in turn encouraged economic growth.
The demand for African labor on plantations transformed a few African societies into slave-export economies. Slave-distribution networks developed in the interior to ensure a regular flow of African captives to coastal outlets, which in turn became slave-export centers with facilities to provision and confine Africans for several months. As prices rose over time, African traders gained a greater share of slaving profits. Some argue that the increasing influx of European goods limited African social and economic development. Access to inexpensive Indian- or European-produced textiles, for example, retarded the growth of African textile industries. Also, guns and alcohol are viewed as "socially disruptive" trading goods, and there was a "slave-gun cycle" whereby Africans sold slaves to acquire more firearms for slave raiding. It is likely, however, that the strength of indigenous African domestic economies meant that the major African impact of the slave trade was social rather than economic. Foreign trade constituted a small percentage of African gross domestic product, and ordinary African peoples would have never seen goods produced outside Africa.
The slave trade undoubtedly increased the incidence of warfare and slave raiding among many African societies. Moreover, as about two-thirds of the captive Africans were men between the ages of 18 and 30, the slave trade likely removed essential workers and soldiers. In response to renewed external threats, villages may have been abandoned as they consolidated with other communities for protection. In certain areas the slave trade altered the ratio of men to women and adults to children, thus prompting further social changes, particularly in kinship structure and marriage patterns. The incidence of slavery increased in Africa during the slave trade era and increased again in the immediate aftermath of abolition, when external demand for slaves ended rather suddenly.
In the Americas the slave trade ensured that, for three centuries, the subtropical areas remained the focal point of New World economic activity. It also ensured a much more complex social milieu and cultural environment than would have been possible without contacts with Africa. With all of its horrors and inhumanity, the transatlantic slave trade was critical in the formation of the modern world.
"Transatlantic Slave Trade," Microsoft® Encarta® Africana. ©&(p) 1999 Microsoft Corporation. All rights reserved.