Percy was born in New York City, New York on the 4th of August, 1890 and he enlisted in the US Navy and although there is not much recorded information about his life, it is known that his actions at Vera Cruz during the Mexican Campaign earned him the Medal of Honor. The citation reads:

On board the U.S.S. Florida during the seizure of Vera Cruz, Mexico, 21 April 1914; for extraordinary heroism in the line of his profession during the seizure of Vera Cruz, Mexico.

Percy Austin Decker received his Medal of Honor on the 15th of June, 1914 and he died on the 18th of August, 1936 at the age of 46. He is buried in Arlington National Cemetery: Section 7, Site 103023.