Transatlantic Slave Trade Begins
The Transatlantic Slave Trade began as a systematic and large-scale movement of enslaved Africans to the Americas, largely initiated by Portuguese and Spanish merchants in the late 15th century. Early practices of slavery, including the trade of African slaves by Arab caravans, set the stage for this expansion. The trade intensified following Christopher Columbus's voyages, during which he advocated for the use of enslaved labor in the New World. By the early 1500s, the Spanish established a demand for African slaves, recognizing their resilience and suitability for labor, particularly on sugar plantations.
The trade grew rapidly, with royal contracts, known as asientos, facilitating the importation of thousands of slaves from Africa to the Americas. Over the next few centuries, the trade expanded to include other European nations, making it one of the most significant maritime commercial ventures in history. It is estimated that between 11 million and 14 million Africans were forcibly transported across the Atlantic, with significant impacts on both the Americas and Africa. The legacy of this trade includes profound social and economic repercussions, contributing to ongoing challenges related to race and inequality in contemporary society.
Transatlantic Slave Trade Begins
Locale The Atlantic coasts of Africa and the Americas
Date 1502
In 1502, the first African slaves were taken to the New World, and eight years later, Spanish king Ferdinand II approved the shipment of 250 additional slaves. The numbers continued to grow until they reached about 10,000 per year by the end of the 1530’s.
Key Figures
Isabella I (1451-1504), queen of Castile, r. 1474-1504Ferdinand II (1452-1516), king of Castile as Ferdinand V, r. 1474-1504, and king of Aragon, r. 1479-1516Charles V (1500-1558), king of Spain as Charles I, r. 1516-1556, and Holy Roman Emperor, r. 1519-1556Juan de Córdoba (fl. early sixteenth century), the first European known to take an African slave to AmericaJuan Rodríguez de Fonseca (1451-1524), head of the Spanish department of Indian affairs, 1493-1524, and chaplain and adviser to Isabella and FerdinandNicolás de Ovando (c. 1451-c. 1511), governor of Spain’ American possessions, 1502-1509, and founder of theencomienda systemBartolomé de Las Casas (1474-1566), Spanish priest and advocate of American Indian rightsJohn III (1502-1557), king of Portugal, r. 1521-1557
Summary of Event
The transatlantic slave trade developed as a logical extension of earlier practices. Since the ninth century, Arab caravans had transported slaves across the Sahara for sale in Mediterranean markets. In 1444, Portuguese ships transported 235 black slaves from the Gulf of Guinea to southern Europe, where most of them were sold as domestic servants. Beginning in the 1470’s, Portuguese merchants operated a large slaving base on the fortified island of São Tomé. By the end of the century, more than thirty thousand African slaves had been shipped to Europe, and an additional seven or eight thousand had been taken to Portuguese plantations in the Cape Verde Islands, Madeira, and the Azores.

After Spain annexed the Canary Islands in 1479, Spanish planters also used slave labor on their sugar plantations. By 1500, the planters had imported about a thousand slaves from the African continent. Since explorer Christopher Columbus looked to the Portuguese and Spanish colonies of the eastern Atlantic as a model, he envisioned the use of slave labor in the colonies he hoped to establish in the western Atlantic. When he landed on the Caribbean islands in 1492, Columbus enthusiastically wrote to the Spanish monarchs that the Indies could provide as many slaves as might be needed. Three years later, he sent about five hundred Caribbean Indian slaves to Europe, the first west-to-east transatlantic slave shipment. Despite Queen Isabella I’s scruples about using as slaves people she saw as her vassals, she approved the enslavement of cannibals and any American Indians captured in “just wars,” which included wars aimed at converting pagans to Christianity.
In 1501, Isabella prohibited the transportation of outside slaves to the Indies for work in plantations and mines. Her government, however, permitted a few individuals to import privately owned house servants. In 1502, Juan de Córdoba, a Seville merchant and friend of Columbus, took an African slave to live and work on the island of Hispaniola (now Haiti and the Dominican Republic). Córdoba’s slave was the first known to have been transported across the Atlantic Ocean to labor in the New World. Later that year, the governor-general of the island, Nicolás de Ovando, also imported three or four African slaves. Soon after Isabella’s death in 1504, the ban on importing slaves ended, and at least seventeen were taken to Hispaniola in 1505.
As Spanish settlers organized mines and large sugar plantations in the Indies, they quickly discovered that the slave labor of the indigenous people was less productive than that of Africans, who were more resistant to European diseases, more accustomed to working with horses, and less likely to escape. In 1509, Governor Diego Columbus, son of the explorer, wrote to King Ferdinand II complaining of a labor shortage and requesting black slaves.
Ferdinand, who was praised by Niccolò Machiavelli, was a pragmatic politician determined to expand his empire, and he saw no moral or legal reasons to oppose the expansion of slavery. His major adviser for imperial affairs, the bishop of Palencia, Juan Rodríguez de Fonseca, strongly supported Governor Columbus’s request. On January 22, 1510, the king instructed the Casa de Contratación, which managed Spanish maritime affairs, to allow 250 slaves (mostly Africans) to be transported to Hispaniola, with a hefty tax to be charged for each new slave.
For the next few years, about fifty slaves a year were sent to the Americas. Meanwhile, the Indian population in the Spanish colonies was rapidly declining because of disease and brutal working conditions. When Charles I became king of Spain in 1516, settlers were clamoring for additional black slaves. Even the humanitarian priest and historian Bartolomé de Las Casas endorsed an increase, for at this time he believed that the importation of Africans would mitigate the cruel treatment of the indigenous population.
On August 18, 1518, Charles issued an asiento (royal contract) authorizing a Flemish courtier, Lorenzo de Gorrevod, to import up to four thousand black slaves from Europe to the American colonies. Gorrevod sold the asiento to several Genoese merchants, and they, in turn, subcontracted with Portuguese middlemen. Charles continued to grant additional asientos for black slaves, who were becoming the majority of laborers on sugar plantations and mills. By 1530, the island of Puerto Rico had about three thousand slaves, ten times the number of Spanish settlers living there.
An important change took place in 1530, when the ship Nuestra Señora de Begoña departed São Tomé with three hundred slaves and sailed directly to Hispaniola. Before this date, business records indicate that almost all slaves had been shipped from Africa to Europe and from there to the Americas. Portugal’s King John III was happy to give permission to merchants to take the direct route. By reducing transportation costs, the change greatly facilitated the growth of transatlantic trade. In the New World, the slaves sold for more than twice the cost of purchasing them in Africa. The transatlantic traffic in slaves had already grown into one of the major sources of profit for private businessmen as well as for the crowns of Spain and Portugal.
In 1532, the Portuguese began importing a tiny number of African slaves into their recently founded settlements in Brazil. Like the Spanish, Portuguese planters soon recognized that the culture of African slaves made them more desirable than Brazilian Indian slaves. Within fifty years, Brazil would develop into one of the major destinations for ships carrying human cargo.
Significance
Historians estimate that by 1600, between 200,000 and 500,000 Africans had been carried to the Americas to work on plantations, in mines, or as house servants. Until then, Portugal and Spain largely dominated the Atlantic slave trade, although other European nations did their best to get a share of the spoils. In 1611, the Dutch built a fort on the Gold Coast. In 1619, English settlers in Jamestown obtained their first slaves from a Dutch privateer. Although a few English ships had made slave voyages as early as the 1560’s, it was not until the 1630’s that the English emerged as major participants in the Atlantic slave trade. The French became actively involved in the trade during the next decade as well.
The transatlantic slave trade was unquestionably one of the largest and most profitable maritime and commercial ventures in all history. By the time the slave trade finally ended in the 1870’s, it is estimated that a total of between eleven million and fourteen million enslaved Africans had been transported across the ocean. About half of these slaves were taken to Brazil, while the area that is now the United States received less than 7 percent of the total migration. The large-scale presence of persons of African ancestry in the Americas is a direct consequence of the transatlantic trade. The injustices and violence of slavery left behind a legacy of poverty, prejudice, and resentment that continues to make racial harmony difficult to achieve.
Most historians think that the slave trade also had a devastating effect on Africa. The economic incentives for tribes to capture and sell slaves promoted an atmosphere of violence and lawlessness. Continuing depopulation and fears of captivity made agricultural and economic development almost impossible. A large percentage of the captives were young men and women who were at the prime age for having children and beginning families. Those left behind were disproportionately elderly, disabled, or otherwise dependent. Some historians argue that the slave trade contributed to the conditions that encouraged European imperialism in Africa during the late nineteenth century.
Bibliography
Blackburn, Robin. The Making of New World Slavery: From the Baroque to the Modern, 1492-1800. London: Verso, 1997. A well-written account by a leading New Left historian, arguing that independent traders and businessmen were more responsible than governments for the cruelties of the slave system.
Donnan, Elizabeth. Documents Illustrative of the Atlantic Slave Trade. 6 vols. New York: Octagon Books, 1968. In addition to original documents, the introduction to volume 1 includes a detailed factual account of the early history of the trade.
Klein, Herbert S. The Atlantic Slave Trade. New York: Cambridge University Press, 1999. A relatively short work that examines the four hundred years of the slave trade from a comparative perspective, outlining both common global features and local differences in the trade.
Northrup, David. Africa’s Discovery of Europe, 1450-1550. New York: Oxford University Press, 2002. An interesting book written from an Afrocentric perspective, attempting to view history through African eyes and presenting Africans as active participants rather than simply as passive victims.
Thomas, Hugh. The Slave Trade: The Story of the Atlantic Slave Trade, 1440-1870. New York: Simon & Schuster, 1997. A comprehensive, scholarly, and balanced narrative that is filled with colorful anecdotes and interesting information about political leaders and businessmen who were involved in the trade.
Thompson, Vincent B. The Making of the African Diaspora in the Americas, 1441-1900. New York: Longman, 1987. An interesting synthesis, asserting that there is no evidence of slavery in Africa before the Portuguese arrived and emphasizing that the slave trade was an integral part of the European quest for wealth and power.