USS Osage was a single-turreted Neosho-class monitor built for the Union Navy during the American Civil War. After completion in mid-1863 by Edward Hartt, the ship patrolled the Mississippi River against Confederate raids and ambushes as part of Rear Admiral David Porter's Mississippi Squadron. Osage participated in the Red River Campaign in March–May 1864, during which she supported the capture of Fort DeRussy in March and participated in the Battle of Blair's Landing in April. The ship was grounded on a sandbar for six months after the end of the campaign and badly damaged. Osage, after being refloated and repaired, was transferred to the West Gulf Blockading Squadron in early 1865 for the campaign against Mobile, Alabama. During the Battle of Spanish Fort in March 1865 she struck a min