Henry was born in 1832 in Ireland and when he joined the US Navy, he served using his middle name as his first. It was his actions on the 10th and 11th of June, 1871 that would earn him the Medal of Honor. The citation reads:

On board the U.S.S. Benicia during the attack on the Korean forts, 10 and 11 June 1871. Carrying out his duties with coolness, Grace set forth gallant and meritorious conduct throughout this action.

Patrick Henry Grace died on the 24th of February, 1896 and is buried in the Holyhood Cemetery in Brookline, Massachusetts; lot 56.