Albert Castel, "Davis, Jefferson Columbus," American National Biography Online, February 2000, http://www.anb.org/articles/05/05-00179.html.
Promoted to brigadier general in December 1861, [Jefferson C. Davis] commanded a division at the battle of Pea Ridge in Arkansas (6-7 Mar. 1862) where he played a key role in securing the Union victory by his promptness and the skill with which he deployed his troops. What seemed to be a bright military future suddenly and permanently became clouded, however, by the most dramatic episode of Davis's career. Assigned, following further service as a division commander in Mississippi in the late spring of 1862, to the command of Major General William Nelson (1824-1862) in Louisville, Kentucky, he was so deeply offended by what he deemed to be an insulting reprimand from Nelson that on the morning of 29 September 1862, accompanied by Governor [Oliver P.] Morton, he went to Nelson's headquarters at the Galt House hotel. Finding Nelson in the lobby, he demanded "satisfaction" for the insult, and when Nelson responded by calling him an "insolent puppy," he threw a wadded-up calling card into Nelson's face. In turn Nelson, who weighed three hundred pounds, slapped Davis in the face and then went upstairs. While he was doing so, Davis procured a revolver and followed him. Hearing Davis, Nelson turned around and started toward him. "Not another step!" cried Davis, who then shot Nelson in the chest, mortally wounding him. Although placed under arrest, Davis was never court-martialed, perhaps because Nelson had forgiven him before dying, and thanks to Morton's political influence he soon received command of a division in the Army of the Cumberland. Nevertheless, his personal reputation was irreparably damaged.