First Lieutenant Michael V. Santo served in the United States Army during the Vietnam War from 1964 to 1966. He was commissioned through the Army Reserve Officers' Training Corps (ROTC) at City College of New York in June 1964.

Lt. Santo was assigned to the 5th Infantry Division (Red Diamond) at Fort Devens, Massachusetts, from 1964 to 1965, where he earned the Expert Infantryman Badge. He then deployed with the First Infantry Division (Big Red One) to Lai Khe, Vietnam, serving as a weapons platoon leader from 1965 to 1966.

He was awarded the Bronze Star Medal with "V" device for heroism in ground combat during the Battle of Ap Nha Mat near the Michelin Rubber Plantation on December 5, 1965. He also received the Vietnam Service Medal, the National Defense Service Medal, and the Combat Infantryman Badge.

His service and sacrifice are remembered with deep respect and gratitude.