Trans-Atlantic Slave Trade, 1510s1860s. The Trans-Atlantic slave trade was an enormous enterprise that lasted for more than three centuries. Mali Metro Map Slaves came largely fromWest and Central Africa, and most were destined for Brazil and the Caribbean. Less than 10 percent were shipped directly from Africa to Britain's colonies on mainland North Country and, after 1776, to the new United States.
(Carto-Graphics) In 1747, the average length of a round-trip slaving voyage from New York was 232 days. This included eight to nine weeks to reach Africa, around sixteen weeks spent trading to obtain slaves, and an additional eight to nine weeks for the return voyage. Slave voyages presented those engaged in the trade with a number of risks. Water travel, though improved by the advances of the seventeenth century, was still a dangerous undertaking as ships were sometimes unable to sustain the hardships of a lengthy voyage.
In 1766, the slave ship Nancy sank after springing a leak. Its captain, crew, and cargo of 59 slaves managed to reach Barbados in the ship's lifeboats. Such instances were not isolated and often did not end so fortunately. In addition, colonial slave traders were the targets of slave ships from other countries. In the late eighteenth century, several New York slave ships were attacked by French privateers and forced to surrender their human cargoes.