But it is important to note that at the time, Jefferson and other founders would have seen slavery as an evil of an age which would soon be past. Jefferson went so far as to write in his own draft of the Declaration that England should be condemned for "holding human beings in bondage." This fact was also pointed out by opponents who noted that if slavery was so evil, why did America not do more to end it?
The American Revolution itself did not result in immediate liberation from slavery for everyone. The only people who were emancipated were those fighting for freedom. Once their military service had ended, those people were free to be re-enslaved if they could not make enough money to support themselves. Also after the war ended, some black soldiers were forcibly transported back across the Atlantic.