After 1809, Jefferson lived in retirement at his beloved Monticello, although he often advised his successors, Madison and James Monroe. One of his cherished ambitions was attained when he was able to bring about the founding of the Univ. of Virginia (see Virginia, Univ. of). President of the American Philosophical Society (1797–1815), Jefferson was a scientist, an architect, and a philosopher-statesman, vitally interested in literature, the arts, and every phase of human activity. He passionately believed that a people enlightened by education, which must be kept free, could govern themselves better under democratic-republican institutions than under any other system.
After the death (1784) of his wife Martha Wayles Skelton, Jefferson did not remarry. During his White House years, Dolley Madison served as his First Lady. In the 1990s long-repeated rumors that he had fathered a child or children by the slave Sally Hemings, his wife's half-sister, appeared to be supported by DNA research. Although the subject remained controversial, in 2000 the Thomas Jefferson Memorial Foundation concluded after an exhaustive study that Jefferson was almost certainly the father of one and quite probably of all six of Hemings's children. Some admirers of Jefferson hold that his younger brother, Randolph, is the more likely father of Hemings's descendants.