William "Bull" Nelson (September 27, 1824 – September 29, 1862) was a United States naval officer who became a Union general during the American Civil War. As a Kentuckian, Nelson could have sympathized with the Confederates but Like his state, he remained loyal to the United States of America. Secretary of Treasury Salmon P. Chase believed Nelson's actions had kept Kentucky loyal and promoted him to brigadier general in September 1861. Nelson's 4th Division bore the brunt of heavy fighting at the Battle of Shiloh and took part in the Siege of Corinth; he was the first man to enter the town.