was 220,000; and the difference, 90,000, may be set down to
importation. Adding, now, 25 percent, to 220,000, we obtain, for 1760,
275,000; whereas the actual number was 310,000, which Would give
35,000 for importation. Pursuing the same course with the following
periods, we obtain the following results:--

Actual Natural Actual
Years Number. Increase. Increase. Importation.
----- ------- --------- --------- ------------
1760..... 310,000..... 77,500..... 152,000..... 74,500
1770..... 462,000..... 115,500..... 120,000..... }
1780..... 582,000..... 140,500..... 170,000..... } 34,000
1790..... 752,000, number given by first census.

For a large portion of the period from 1770 to 1790, there must have
been a very small importation; for during nearly half the time the
trade with foreign countries was almost altogether suspended by the
war of the revolution.

If we add together the quantities thus obtained, we shall obtain a
tolerable approximation to the number of slaves imported into the
territory now constituting the Union, as follows:--

Prior to 1714..................................... 30,000
1715 to 1750...................................... 90,000
1751 to 1760...................................... 35,000
1761 to 1770...................................... 74,500
1771 to 1790...................................... 34,000
And if we now estimate the import
subsequent to 1790 at even........................ 70,000