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 1698 and 1707. The importation then dwindled,
but rose after the Assiento to perhaps 30,000. The proportion, too, of
these slaves carried to the continent now began to increase. Of about
20,000 whom the English annually imported from 1733 to 1766, South
Carolina alone received some 3,000. Before the Revolution, the total
exportation to America is variously estimated as between 40,000 and
100,000 each year. Bancroft places the total slave population of the
continental colonies at 59,000 in 1714, 78,000 in 1727, and 293,000 in
1754. The census of 1790 showed 697,897 slaves in the United States.[17]

In colonies like those in the West Indies and in South Carolina and
Georgia, the rapid importation into America of a multitude of savages
gave rise to a system of slavery far different from that which the late
Civil War abolished. The strikingly harsh and even inhuman slave codes
in these colonies show this. Crucifixion, burning, and starvation were
legal modes of punishment.[18] The rough and brutal character of the