USS Persistent (AM-491/MSO-491) was an Aggressive-class minesweeper acquired by the U.S. Navy for the task of removing mines that had been placed in the water to prevent the safe passage of ships. The second ship to be named Persistent by the Navy, MSO–491 was laid down 17 June 1954 as AM491 by J.M. Martinac Shipbuilding Corp., Tacoma, Washington; reclassified MSO–491 on 7 February 1955; launched 23 April 1955; sponsored by Mrs. M.S. Erdahl; and commissioned 3 February 1956, Lt. Theodore R. Johnson in command.