In his original draft of the Declaration of Independence, Jefferson blames the British (and really, just the British king) for the international slave trade? Why? Wouldn't he see the Americans as just as culpable?
But then researching this question, I found out that Jefferson banned the international slave trade into Virginia in 1778, and most of the other states followed suit. The constitution prohibited banning the international slave trade for 20 years after its adoption, but then in 1807, the international slave trade was banned in a law signed by Jefferson. Why did the framers of the constitution put off banning the international slave trade, and how did that consensus to ban it develop during the intervening twenty years?
Finally, I know that the Confederate constitution also banned the international slave trade. Why was someone like Jefferson so much more willing to ban the international slave trade than to free his own slaves or abolish slavery? Why did Confederates, who were willing to fight a devastating war to protect slavery, willing to ban the international slave trade in their constitution?
There's a really good book on this subject called Forced Founders. I don't have it with me, but you should definitely check it out if you have access to a university library.
Basically, Virginia was slowly becoming blacker due to the growth of the number of slaves. There were constant rumors (and real incidents!) of slaves murdering their masters and planning a full race war. With attacks rising faster than black population growth, there was a real feeling that once the colony became majority black, the Old Dominion would be in real danger.
The established planter aristocracy wanted to ban imports of new slaves. This would also have the effect of increasing the value of their stock, as any westward expansion of Virginia slavery would have to come from them. However, the British government vetoed the ban on slave importation, due to its extreme profitability.
Hope this helps