He scored six aerial victories as a flying ace during World War II, and was the recipient of the Navy Cross for shooting five enemy planes down in one day.

[1] Valentine's first duty station was in St. Thomas in the Virgin Islands, where he spent one year flying anti-submarine patrols.

[1] On May 25, 1945, Captain Valentine led a division of four F4U Corsairs in a daring attack against 30 Japanese fighter and bomber aircraft which were approaching Okinawa from the north.

In 1950, during the first year of the Korean War, Master Sergeant Valentine flew over 120 missions with Marine Observation Squadron 6 (VMO-6).

[5] He was shot down a second time over enemy territory, but again he managed to evade capture and return to friendly lines.