Henry Knox Thatcher (26 May 1806 – 5 April 1880) was a rear admiral in the United States Navy, who served during the American Civil War. Biography Early life and career He was born in Thomaston, Maine to Lucy Flucker (née Knox) and Ebenezer Thatcher, the daughter of Major General Henry Knox and Lucy Flucker Knox. Appointed to the U.S. Military Academy at West Point in 1822, Thatcher was absent on sick leave for most of the first year and resigned in April 1823. He then received an appointment as a midshipman in the Navy on 4 March 1823. Thatcher spent most of the next four years on board the frigate in the Pacific. He became a passed midshipman on 4 March 1829, and in 1830-1831 served in the schooner and sloop of war in the West Indies. He was promoted to lieutenant on 28 February 1833 and served aboard the schooner in Chesapeake Bay. He then served on the frigate in the Mediterranean Squadron in 1834–35; had special duty in 1837; and returned to the Mediterranean in the frigate in 1840. He served aboard the receiving ship at Boston in 1843–46, then in the sloop-of-war , part of the Africa Squadron in 1847–50. After duty at Boston Navy Yard in 1851, he commanded the storeship in 1852. Promoted to commander on 14 September 1855, while serving as Executive Officer of the Naval Asylum at Philadelphia, Thatcher then commanded the small sloop of war in the Pacific in 1857–59. He was Executive Officer of the Boston Navy Yard from November 1859 to November 1861, and thus played a role in the vast expansion of the Navy that began with the outbreak of the Civil War in April 1861. Civil War He was promoted to captain in 1861, and while commanding the large sloop of war in the Mediterranean, attained the rank of commodore on 3 July 1862. He commanded the screw frigate in the North Atlantic Blockading Squadron in 1864–65, and a division of Admiral Porter's Squadron at the two battles of Fort Fisher in December 1864 and January 1865. Thatcher was then appointed to command of the Western Gulf Squadron, immediately commencing operations in cooperation with General Canby, commander of the Army of West Mississippi, in the capture of Mobile, Alabama. After a brief and vigorous bombardment, Spanish Fort and Fort Blakeley were captured by the Union Army on