He participated in the African Slave Trade Patrol, fought in the American Civil War, and served as commander of the Asiatic and Pacific Squadrons.

[3][4] Assigned to the sidewheel steamer USS Fulton in the Home Squadron from 1854 to 1856, Irwin was promoted to master on 16 September 1855 and then to lieutenant on the same day.

The American Civil War broke out in April 1861, and Irwin saw a great deal of action against Confederate forces aboard Wabash.

[3][4] After spending 1872 on duty at League Island in Philadelphia, Irwin was commanding officer of the sailing frigate USS Sabine, then operating as a training ship, from 1873 to 1875.

He was idle, awaiting orders, from 13 December 1889 to 12 July 1890, when he assumed duties as a member of the Board of Inspection and Survey.

Irwin soon became involved in the "Black Week" crisis of December 1893 – January 1894, during which war nearly broke out between the United States and the Provisional Government of Hawaii.

He left behind his wife, a daughter, and a son, also named John Irwin, who at the time was paymaster aboard the training ship USS Essex.