"It were doubtless to be wished, that the power of prohibiting the importation of slaves had not been postponed until the year 1808, or rather that it had been suffered to have immediate operation. But it is not difficult to account, either for this restriction on the general government, or for the manner in which the whole clause is expressed. It ought to be considered as a great point gained in favor of humanity, that a period of twenty years may terminate forever, within these States, a traffic which has so long and so loudly upbraided the barbarism of modern policy; that within that period, it will receive a considerable discouragement from the federal government, and may be totally abolished, by a concurrence of the few States which continue the unnatural traffic, in the prohibitory example which has been given by so great a majority of the Union."
- James Madison (Federalist Paper No. 42)