Jefferson’s first draft of the Declaration of Independence contained a critique of King George III’s involvement in the slave trade. Although not approved by the entire Second Continental Congress, it indicates that the leading Founders understood the slavery issue in moral terms.
…He has waged cruel war against human nature itself, violating its most sacred rights of life and liberty in the persons of a distant people who never offended him, captivating and carrying them into slavery in another hemisphere, or to incur miserable death in their transportation thither. This piratical warfare, the opprobrium of infidel powers, is the warfare of the Christian king of Great Britain. Read more