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.
Jefferson, along with many other Americans, combined plans for emancipation with colonization―moving freed slaves outside the U.S. "I have seen no proposition so expedient . . . as that of emancipation of those [slaves] born after a given day, and of their education and expatriation at a proper age," Jefferson wrote in 1814.
He eventually decided that Africa was the best destination.