The third USS Lexington was a timberclad gunboat in the United States Navy during the American Civil War. Purchase and conversion Lexington was built as a sidewheel steamer at Pittsburgh, Pennsylvania, in 1861 and was purchased by the War Department and converted into a gunboat at Cincinnati, Ohio, under the direction of Commander John Rodgers. The gunboat, operated by the navy, joined the army's Western Flotilla at Cairo, Illinois, 12 August 1861. On 22 August, she seized steamer W. B. Terry at Paducah, Kentucky, and on 4 September, with , she engaged Confederate gunboat Jackson and southern shore batteries at Hickman and Columbus, Kentucky. On 6 September, the two gunboats spearheaded General Ulysses S. Grant's drive to seize strategic Paducah and Smithland, Kentucky, at the mouths of the Tennessee and Cumberland Rivers. In his first use of strength afloat, Grant countered a Confederate move into the state, helping preserve Kentucky for the Union and foreshadowing his skillful use of naval mobility and support during the coming campaigns which divided the Confederacy and won the entire Mississippi system for the Union. Lexingtons next action came on the 10th when she and silenced a Confederate battery and damaged Jackson at Lucas Bend, Missouri, while covering a troop advance. An 8-inch shell from Lexington exploded in Jacksons starboard wheelhouse causing severe damage. Only the powerful batteries on the bluffs at Columbus, Kentucky, saved Jackson and another Southern steamer from capture. Battle of Belmont After accompanying an expedition to Owensboro, Kentucky, on 22–25 September, Lexington again engaged the batteries of Columbus on 7 October. With Tyler a month later, she protected General Grant's army during the Battle of Belmont silencing enemy batteries which opposed the landings. When a large number of fresh Confederate troops threatened Grant's men, well directed fire of grape and canister from Lexington and Tyler scattered the Southern reinforcements enabling the Union soldiers to reach safety on their transports. Battle of Fort Henry The Western Flotilla steamed up the Tennessee River to attack Fort Henry which guarded this water approach to the South's heartland. Although the operation was originally planned as a joint expedition, heavy rains for 2 days before the attack delayed troop movements so the gunboats attacked alone 6 February 1862. Accurate fire from the gunboats pounded the fort and forced Brigadier General Lloyd Tilghman, CSA, with all but four of his defending guns useless, to strike his flag.