Stephen Clegg Rowan, a vice admiral in the United States Navy, who serves during the Mexican–American War and the American Civil War, is born in Dublin on December 25, 1808. He has a 63-year career, which is one of the longest in the history of the United States Navy.

Rowan comes to the United States at the age of ten and lives in Piqua, Ohio. He is a graduate of Miami University and is appointed as a midshipman in the U.S. Navy on February 1, 1826 at the age of seventeen. Later, he takes an active role in the Mexican–American War, serving as executive officer of the sloop-of-war USS Cyane during the capture of Monterey, California on July 7, 1846, and in the occupation of both San Diego and Los Angeles. In January 1847 he leads a provisional battalion, with the nominal rank of major, of seven companies of naval infantry (along with a company of artillery and a company of sappers and miners) for the recapture of Los Angeles.

Captain of the steam sloop USS Pawnee at the outbreak of the American Civil War, he attempts to relieve Fort Sumter and burn the Norfolk Naval Shipyard. In the fall of 1861, he assists in the capture of the forts at Hatteras Inlet. Then, taking command of a flotilla in the North Carolina sounds, he cooperates in the capture of Roanoke Island in February 1862. Promoted simultaneously to captain and commodore for gallantry, he then supports the capture of Elizabeth City, Edenton, and New Bern. During the summer of 1863, he commands the broadside ironclad USS New Ironsides on blockade duty off Charleston, South Carolina and the following August assumes command of Federal forces in the North Carolina sounds. During this time the rebel semi-submersible CSS David attacks the USS New Ironsides with a spar torpedo. In the ensuing explosion, one man is killed and a large hole is torn into the ironclad but she continues her blockading duties.

Commissioned rear admiral on July 25, 1866, Rowan serves as commandant of the Norfolk Naval Shipyard until 1867, when he assumes command of the Asiatic Squadron. Returning in 1870, he is appointed vice admiral, following the death of Admiral David Farragut and the promotion of Vice Admiral David Dixon Porter in August of that year. In December 1870 he reaches the mandatory retirement age of 62 but, like admirals Farragut and Porter before him, he is allowed to remain on active duty.

Rowan serves as commandant of the New York Navy Yard from 1872 to 1876, as governor of the Philadelphia Naval Asylum at Philadelphia, Pennsylvania, in 1881, and as superintendent of the United States Naval Observatory, Washington, D.C., from 1882 until his retirement in 1889.

In 1882 Rowan is elected as a First Class Companion of the District of Columbia Commander of the Military Order of the Loyal Legion of the United States (MOLLUS). He is assigned MOLLUS insignia number 2510. His son, Hamilton Rowan, an officer in the United States Army, is elected as a Second Class Companion of MOLLUS and becomes a First Class Companion upon his father’s death.

Rowan dies at the age of 81 in Washington, D.C. on March 31, 1890.