He even went so far as to say that it was an “abominable crime”. Jefferson favored gradual emancipation (freedom) that would eventually allow slaves to leave the United States. Jefferson believed that relations between whites and blacks were so hostile and inhumane that they could not function together in a stable society. Jefferson calmed down in his protests against slavery when he began to realize how difficult it would be to end slavery. Everything he had learned growing up would completely change, and not just for him but for many others. But even though it seemed difficult or impossible, he decided he wouldn't give up. The slaves had no voice, so he spoke on their behalf. In 1776, Jefferson launched a scathing attack on the slave trade in the proposed Declaration of Independence. The Continental Congress scrapped the draft, disagreeing with Jefferson's views. When Jefferson became president in 1808, he encouraged legislation that ended the Americas' participation in the international slave trade, but the buying and selling of slaves continued within the country..