Jefferson is a central figure in early American history, highly praised for his political leadership, but also criticized for the role of slavery in his private life. He championed equality, democracy and republicanism, attacking aristocratic and monarchistic tendencies. He was a leader in American independence, advocated religious freedom and tolerance, and opposed the centralizing tendencies of the urban financial elite. He formed the second national political party and led it to dominance in 1800, then worked for western expansion and exploration. Critics decry the contradiction between his ownership of hundreds of slaves and his famous declaration that "all men are created equal", and argue that he fathered children with his slave mistress.