History
United States
Laid down	date unknown
Launched	in 1859 at Brownsville, Pennsylvania
Acquired	18 May 1862
In service	c. May 1862
Out of service	at war’s end
Stricken	1865 (est.)
Fate	Sold, 17 August 1865
General characteristics
Displacement	123 tons
Length	not known
Beam	not known
Draught	not known
Propulsion	steam engine stern wheel-propelled
Speed	not known
Complement	not known
Armament	two 12-pounder rifled guns

The USS T. D. Horner was a stern-wheel steamer built in 1859 at Brownsville, Pennsylvania and was part of Colonel Charles Ellet, Jr.'s United States Ram Fleet during the American Civil War.

The ship was purchased by the War Department on 18 May 1862 for use on the Mississippi River and its tributaries in the Army's newly established flotilla which was popularly known as the "Ellet Ram Fleet."

Commanded and manned by Union Army personnel, this organization operated in the same waters as the Western Flotilla (later to become the Mississippi Squadron) which had been established the previous summer, also under Army auspices but commanded and manned by Navy personnel.

The relationship between these organizations, which often cooperated in carrying out their overlapping missions, was never completely clarified. However, at no time was the Ram Fleet, or were its ships, taken into the Navy. T. D. Horner served the Ram Fleet and its successor, the Mississippi Marine Brigade, as a tug until the latter was dissolved on 24 August 1864.

After the Civil War ended, T. D. Horner was sold by the Government on 17 August 1865. She was re-documented for merchant service on 27 November 1865 and plied the Mississippi and its tributaries until New Year's Day 1868 when she hit a bridge at Louisville, Kentucky, and was damaged beyond economical repair.

 This article incorporates text from the public domain Dictionary of American Naval Fighting Ships. The entry can be found here.