Lieutenant John W. Kelley was born in County Antrim, Northern Ireland and emigrated with his family to the United States to settle in Pennsylvania in 1849. He entered the USNA as a midshipman on 31 January 1853 and remained there until June 1857.
Kelley received his first sea orders in June 1857 to the U.S.S. Mississippi, where aboard her he spent two and a half years cruising the Western Pacific. The Mississippi returned to Boston in January 1860 and Kelley returned to the USNA. He graduated in June 1860 and received orders to the U.S.S. Brooklyn, commanded by the then CAPT David G. Farragut.
In December 1860, Kelley was then ordered to the U.S.S. St. Mary's which was cruising the Pacific. Out of boredom and wanting to participate in the war, in 1862 he requested orders to a new command. He was granted his request and detached from the St. Mary's and was attached to the U.S.S. Sabine as her executive officer on 21 April 1862.
The Sabine went out of commission and was put into ordinary in October 1863 ("put in mothballs" to use modern Navy parlance). Kelley volunteered for duty on an iron-clad for his next command. He was ordered to the U.S.S. Tecumseh, then being built in New Jersey, as her executive officer.
LT Kelley was aboard the Tecumseh during the 5 August 1864 Battle of Mobile Bay and died when she was sunk by an underwater mine.