USS Lancaster (1855)

USS Lancaster follows her sister ship USS Switzerland past the Vicksburg batteries, 25 March 1863
History
Laid down:	1855 at Cincinnati, Ohio
Acquired:	1862
Fate:	Sunk 25 March 1863
General characteristics
Displacement:	257 tons
Length:	176 ft (54 m)
Beam:	unknown
Draught:	unknown
Speed:	unknown
Complement:	unknown
Armament:	none

The USS Lancaster was a sidewheel civilian steamer tow boat built in 1855 at Cincinnati, Ohio. Originally it was named Lancaster Number 3 then the Kosciusko. In March through May 1862, she was purchased and converted to a ram by Lt. Col. Charles Ellet, Jr. for the War Department early in April 1862 to serve during the American Civil War.

After fitting out, she steamed down the Ohio river to join the Ellet Ram Fleet being organizing to counter Confederate rams in the Mississippi River.

On 10 May the Confederate ram flotilla, known as the River Defense Fleet, attacked Union gunboats and mortar schooners at Plum Point Bend, Tennessee, sinking Cincinnati and forcing Mound City aground. A fortnight later all but one of the rams had joined the Union flotilla above Fort Pillow ready for action. As the ram fleet and western flotilla prepared to attack, General Halleck’s capture of Corinth, Mississippi, 30 May, cut the railway lines which supported the Confederate positions at Forts Pillow and Randolph forcing the South to abandon these river strongholds.

The Confederacy charged its River Defense Fleet with the task of stemming the Union advance down the Mississippi. The South's strategy called for a naval stand at Memphis, Tennessee.

On the evening of 6 June, Flag Officer Charles Henry Davis arrived above the city with his ironclads. Before dawn the next morning the Union ships raised their anchors and dropped downstream by their sterns. Half an hour later the Confederate rams got underway from the Memphis levee and opened fire, beginning the Battle of Memphis.