Overton enlisted into the U.S. military on September 3, 1940 at Fort Sam Houston, Texas.
He served in the South Pacific from 1940 through 1945, including stops in Hawaii, Guam, Palau and Iwo Jima. He left the U.S. Army in October 1945 as a technician fifth grade.
Overton worked at local furniture stores before taking a position with the Texas Department of the Treasury (now part of the Texas Comptroller of Public Accounts) in Austin. He was married twice but never had children.
Overton lives in Austin, Texas. In November 2015, he was hospitalized there for pneumonia at the age of 109.
A week after celebrating his 111th birthday in May 2017, he was once again hospitalized for pneumonia.
In August 2017, Overton was hospitalized in Austin for pneumonia in both of his lungs.