Philip was born on the 17th of March, 1865, in Belmullet, Ireland, and he enlisted in the US Marine Corps in July of 1887 in Philadelphia, Pennsylvania. He was a Sergeant during the Battle of Cienfuegos during the Spanish-American War and it was his actions during the cutting of a communications cable that would earn him the Medal of Honor. The citation reads:

On board the U.S.S. Nashville during the operation of cutting the cable leading from Cienfuegos, Cuba, 11 May 1898. Facing the heavy fire of the enemy, Gaughan set an example of extraordinary bravery and coolness throughout this action.

Philip received his Medal of Honor on the 7th of July, 1899 and continued to serve in the Marines. While still on active duty as a First Sergeant, Philip Gaughan died on the 31st of December, 1913 at the age of 48. He is buried in the Holy Cross Cemetery in Yeadon, Pennsylvania: Section 54, Range 12, Lot 42.