As captain of a 100-pounder rifle gun on topgallant forecastle on board the U.S.S. Richmond during action against rebel forts and gunboats and against the ram Tennessee in Mobile Bay, 5 August 1864. Despite damage to his ship and the loss of several men on board as enemy fire raked her decks, Sharp fought his gun with skill and courage throughout a furious two-hour battle which resulted in the surrender of the rebel ram Tennessee and in the damaging and destruction of batteries at Fort Morgan.