it. The first introduction of slaves is not imputable to the present
generation, nor even to their ancestors. Before the year 1642, the trade
and ports of the colonies were open to foreigners equally as those of
the mother country; and as early as 1620, a few years only after the
planting of the colony of Virginia, and the same year in which the first
settlement was made in the old colony of Plymouth, a cargo of negroes
was brought into and sold as slaves in Virginia by a foreign ship. From
this beginning, the importation of slaves was continued for nearly
two centuries. To her honor, Virginia, while a colony, opposed the
importation of slaves, and was the first State to prohibit the same, by
a law passed for this purpose in 1778, thirty years before the general
prohibition enacted by Congress in 1808. The laws and customs of the
States in which slavery has existed for so long a period, must have had
their influence on the opinions and habits of the citizens, which ought
not to be disregarded on the present occasion.

* * * * *

When the general convention that formed the Constitution took this
subject into their consideration, the whole question was once more
examined; and while it was agreed that all contributions to the common
treasury should be made according to the ability of the several States
to furnish the same, the old difficulty recurred in agreeing upon a
rule whereby such ability should be ascertained, there being no simple
standard by which the ability of individuals to pay taxes can be
ascertained. A diversity in the selection of taxes has been deemed
requisite to their equalization. Between communities this difficulty is
less considerable, and although the rule of relative numbers would not
accurately measure the relative wealth of nations, in States in the
circumstances of the United States, whose institutions, laws, and