During his presidency, Jefferson was for the most part publicly silent on the issue of slavery and emancipation, as the Congressional debate over slavery and its extension caused a dangerous north–south rift among the states, with talk of a northern confederacy in New England. The violent attacks on white slave owners during the Haitian Revolution due to injustices under slavery supported Jefferson's fears of a race war, increasing his reservations about promoting emancipation at that time. After numerous attempts and failures to bring about emancipation, Jefferson wrote privately in an 1805 letter to William A. Burwell, "I have long since given up the expectation of any early provision for the extinguishment of slavery among us." That same year he also related this idea to George Logan, writing, "I have most carefully avoided every public act or manifestation on that subject."