labor supply. The slave traders found it very easy to seize Negroes in Africa and make great profits by selling them in Southern ports. The English Royal African Company sent to America annually between 1713 and 1743 from 5,000 to 10,000 slaves.[1] After a time, when the Negroes were so numerous that whole sections were overrun, the Southern colonies tried ineffectually to curb the trade. Virginia in 1710 placed a duty of five pounds on each slave but the Royal Governor vetoed the bill. Bills of like import were passed in other colonies from time to time, but the English crown disapproved in every instance and the trade, so lucrative to British shipowners, went on. At the time of the Revolution, there were almost half a million slaves in the colonies.[2] The exact proportions of the slave trade to America can be but approximately determined. From 1680 to 1688 the African Company sent 249 ships to Africa, shipped there 60,783 Negro slaves, and after losing 14,387 on the middle passage, delivered 46,396 in America. The trade increased early in the eighteenth century, 104 ships clearing for Africa in 1701; it then dwindled until the signing of the Assiento, standing at 74 clearances in 1724. The final dissolution of the monopoly in 1750 led — excepting in the years 1754-57, when the closing of Spanish marts sensibly affected the trade — to an extraordinary development, 192 clearances being made in 1771. The Revolutionary War nearly stopped the traffic, but by 1786 the clearances had risen again to 146.
To these figures must be added the unregistered trade of Americans and foreigners. It is probable that about 25,000 slaves were brought to America each year between
