USS Signal, a 190-ton stern-wheel "tinclad" river gunboat, was built in 1862 at Wheeling, Virginia, for commercial use. Acquired by the Navy in August 1862, she was commissioned a few months later. During November and December 1862, Signal took part in expeditions up the Yazoo River, including pioneering mine clearance operations. She was a participant in the capture of Fort Hindman, Arkansas, in January 1863. For much of the of the first half of that year, she operated on the Yazoo River in support of the campaign to capture Vicksburg, Mississippi. Signal patrolled the Mississippi during the remainder of 1863 and into the next year. On 5 May 1864 she was disabled by Confederate artillery fire on the Red River, Louisiana, and was destroyed to prevent capture.