Tenant McLanahan was an officer in the United States Navy

United States Navy

The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...

 during the Mexican-American War.

Biography

Born in Louisiana

Louisiana

Louisiana is a state located in the southern region of the United States of America. Its capital is Baton Rouge and largest city is New Orleans. Louisiana is the only state in the U.S. with political subdivisions termed parishes, which are local governments equivalent to counties...

, McLanahan was appointed midshipman

Midshipman

A midshipman is an officer cadet, or a commissioned officer of the lowest rank, in the Royal Navy, United States Navy, and many Commonwealth navies. Commonwealth countries which use the rank include Australia, New Zealand, South Africa, India, Pakistan, Singapore, Sri Lanka and Kenya...

 12 December 1839 and passed midshipman 2 July 1845. He served in Preble

USS Preble (1839)

USS Preble was a United States Navy sloop-of-war with 16 guns, built by the Portsmouth Navy Yard, Kittery, Maine, launched June 13, 1839 and commissioned in 1840. She was named after Commodore Edward Preble ....

 in the Mediterranean Squadron; in Delaware

USS Delaware (1820)

The third USS Delaware of the United States Navy was a 74-gun ship of the line, named for the state of Delaware.She was laid down at Norfolk Navy Yard in August 1817 and launched on 21 October 1820...

, Brandywine

USS Brandywine (1825)

USS Brandywine was a wooden-hulled, three-masted Frigate of the United States Navy bearing 44 guns which had the initial task of conveying the Marquis de Lafayette back to France...

, and Macedonia

USS Macedonian (1836)

The second USS Macedonian, was a three-masted, wooden-hulled sailing frigate bearing 36-guns of the US Navy and was rebuilt from the keel of the first at Gosport Navy Yard, Portsmouth, Virginia, beginning in 1832; and was launched and placed in service in 1836, Capt...

 in the Brazil

Brazil Squadron

The Brazil Squadron, the Brazil Station, or the South Atlantic Squadron was an overseas military station established by the United States in 1826 to protect American commerce in the South Atlantic during a war between Brazil and Argentina...

, African, and East Indian Squadrons, 1840–45; and in Shark

USS Shark (1821)

The first USS Shark was a schooner in the United States Navy. Built in the Washington Navy Yard, Shark was launched on 17 May 1821. On 11 May 1821, Matthew C. Perry was ordered to take command of Shark, and the ship was ready to receive her crew on 2 June 1821.-History:Shark sailed from the...

, Portsmouth and Cyane

USS Cyane (1837)

The second USS Cyane was a sloop-of-war in the United States Navy during the Mexican-American War.Cyane was launched 2 December 1837 by Boston Navy Yard. She was commissioned in May 1838, Commander John Percival in command....

 in the Pacific Squadron

Pacific Squadron

The Pacific Squadron was part of the United States Navy squadron stationed in the Pacific Ocean in the 19th and early 20th centuries. Initially with no United States ports in the Pacific, they operated out of storeships which provided naval supplies and purchased food and obtained water from local...

, 1846-48.

While attached to Cyane, he was one of Lieutenant Charles Heywood

Charles Heywood

Major General Charles Heywood was the ninth Commandant of the Marine Corps. He served as an officer for over 45 years and was the first Marine to reach the rank of major general...

’s party besieged by Mexican

Mexico

The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...

 forces at the Siege of San José del Cabo

Siege of San José del Cabo

The Siege of San José del Cabo, from January to February 1848, was a prolonged battle of the Mexican-American War in which Mexican militia besieged a smaller force of American marines, sailors and Californio militia...

, Baja California

Baja California

Baja California officially Estado Libre y Soberano de Baja California is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is both the northernmost and westernmost state of Mexico. Before becoming a state in 1953, the area was known as the North...

, 24 January to 14 February 1848. The small group had been left by Commodore William Shubrick

William Shubrick

William Branford Shubrick was an officer in the United States Navy. His active-duty career extended from 1806 to 1861, including service in the War of 1812 and the Mexican-American War; he retired in the early months of the Civil War.-Biography:Born at "Belvedere," Bull's Island, South Carolina,...

to defend San Jose. He conducted himself in a "gallant, unflinching, and devoted manner" as Heywood's second-in-command, until he was killed by a rifleshot in the neck 11 February 1848.