In the summer of 1801, Elder John Leland persuaded the ladies of his Baptist congregation in Cheshire, Massachusetts, to manufacture a "mammoth cheese." He intended to present it to President Jefferson in honor of his republicanism and his support of religious liberty.
Drawing upon Enlightenment criticism of unlawful authority, Jefferson wrote this essay for the Virginia delegation to the First Continental Congress. He accused King George III of imposing illegal control over Virginia’s political decisions, including its desire to restrict or outlaw slavery. Jefferson wrote, “The abolition of domestic slavery is the great object of desire in those colonies.”
At the end of the 18th century, Jefferson and many other Americans believed that stopping the import of enslaved people from Africa and the Caribbean would hasten the end of slavery.
In 1807, three weeks before Britain abolished the Atlantic slave trade, President Jefferson signed a law prohibiting “the importation of slaves into any port or place within the jurisdiction of the United States."
Throughout his life, Jefferson privately endorsed a plan of gradual emancipation, by which all people born into slavery after a certain date would be freed and sent beyond the borders of the United States when they reached adulthood.
He published a short description of this plan in his book Notes on the State of Virginia.