slave trade, Africa and the 363 slavery in the New World spurred trade in slaves The fact that demand for slaves outpaced the growth in supply by natural increase nearly everywhere in the Americas perpetuated the slave trade over four centuries PORTUGAL LEADS SLAVE TRADE Portugal monopolized the trade at the outset The Treaty of Tordesillas in 1494 granted Portugal access to Africa and with it, slaves After 1528, Portuguese shipping companies supplied Spain with slaves through a series of asientos, or contracts An asiento specified the delivery of slaves in piezas de India, which quantified labor rather than slaves Men tallied more piezas than women because of the expectation that men would yield more labor than women For the same reason, the young were worth more than the old A cargo of 100 piezas constituted the smallest number of slaves if all were young males and the largest if all were elderly females Of course slave traders rarely got the “ideal” of all young men fit for the rigors of the plantation Market conditions yielded a mix, with a majority being young men with some women also included, particularly those of childbearing age in hopes of perpetuating the slave population by reproduction A cargo might also contain the prepubescent and elderly because of their low prices Their purchase, however, entailed risk because they were susceptible to disease and early death The value of labor and therefore of slaves fluctuated over time In 1693, the records of the Portuguese Cacheau Company reveal that one pieza was worth 1.6 slaves In 1715, however, records of the South Sea Company of Great Britain reveal that the value of one pieza had declined to 1.04 slaves These figures imply an increase in the demand for slaves over time Supply rose to meet demand Between 1521 and 1550, Spain imported into its colonies 15,000 slaves, 500 per year on average, and between 1551 and 1595, they brought in 36,300 slaves, amounting to 810 per year on average The largest importer of slaves, Brazil, imported more than 200,000 during these years In total Portugal had shipped 264,000 slaves to the New World by 1600 Portugal so dominated trade that by 1600, its maritime rival Britain had shipped only 2,000 slaves to the Americas No other nation participated in the trade until after 1600 Portugal’s trade in slaves benefited from political instability in Africa War engulfed the empire of Jolof, spanning modern Senegal and Gambia, in the middle of the 16th century Warlords enslaved prisoners, trading them with Portugal for guns At the same A slave trader identified as Captain Kimber orders the torture of a young enslaved African woman aboard his ship time, the deterioration of the central government of Kongo, modern Angola, Cabinda, and the Republic of the Congo permitted the Portuguese access to the interior of the kingdom and to a larger number of slaves than had been possible when Kongo confined Portugal to the coast In 1614, Portugal allied with the Jaga, a group hostile to the Ndongo rulers of Angola The resulting war won Portugal captives it sold as slaves New alliances after 1640 gave Portugal access to slaves in Luanda, the modern capital of Angola Political instability gave Europeans more slaves than they might otherwise have expected, for Africa was impenetrable to Europeans into the 19th century Tropical diseases made it hazardous for Europeans to roam the interior of the continent in search of slaves Where African tribes remained united, they kept Europeans at arm’s length Instead, Europeans established fortresses along the western coast of Africa, the first at Elmina, a town in Ghana, in 1482, and awaited the delivery of slaves from African merchants and chieftains Once at the coast, slaves waited in dungeons, pens, or stockades until the arrival of a ship Both Africans and Europeans, intermingling for the first time, were at risk of disease Confinement in tight quarters on the coast and aboard ship exacerbated the danger to Africans of an epidemic SLAVE SHIP CONDITIONS Once onboard the ships, slaves endured lengthy waits until the captain had enough slaves and the right force