A native of Oxford, Michigan, Lantry enlisted in the U.S. Army after graduating from high school. He spent three years in the Army, including service in the Vietnam War. Lantry's experiences in Vietnam and Michigan were the subject of Michael Rosenberg's 2008 book, War As They Knew It: Woody Hayes, Bo Schembechler, and America in a Time of Unrest. Lantry later recalled, "For a full year, my parents agonized, hoping they wouldn't get the call that so many other parents received." In 2007, Lantry described himself as "a proud Vietnam veteran".