He was born in Sinepuxent, Maryland, and was appointed midshipman in the Navy on April 30, 1798, serving on USS United States. His father, Stephen Decatur, Sr., was also a Naval officer, having commanded several ships. The third Stephen Decatur(1815-76) was his nephew and a Commodore in the Navy.
He was active during the undeclared war with France over the next two years. He was promoted to the rank of Lieutenant in 1799. Given command of the brig Argus in 1803, he took to the Mediterranean for war service against Tripoli. Once in the combat zone, Lieutenant Decatur commanded the schooner Enterprise and, on 23 December 1803, captured the enemy ketch Mastico. That vessel, taken into the U.S. Navy under the name Intrepid, was used by Decatur on 16 February 1804 to execute a night raid into Tripoli harbor to destroy the former U.S. frigate Philadelphia, which had been captured after running aground at the end of October 1803.
This daring and extremely successful operation made Lieutenant Decatur an immediate national hero, a status that was enhanced by his courageous conduct during the 3 August 1804 bombardment of Tripoli. In that action, he led his men in hand-to-hand fighting while boarding and capturing an enemy gunboat. Decatur was subsequently promoted to the rank of Captain, and over the next eight years had command of several frigates.
On October 25, 1812, now commanding United States, he captured HMS Macedonian. In 1814 he flew a pennant as Commodore commanding USS President and three smaller vessels in the West Indies. Unfortunately he fell in with the British West Indies Squadron January 15, 1815, and had to surrender President after a fierce fight.
Decatur is famed for his toast "Our country! In her intercourse with foreign nations may she always be in the right; but our country, right or wrong."
- The Stephen Decatur House Museum: Washington, DC