He married Ellen Dygert (1892 - 1977) and had four children: Kathryn, Gilbert, George, and Ellen.
After the war, Hershey remained in the army and transferred to the regular forces. He was promoted to captain in the United States Army in 1920. He attended the Command and General Staff College and the Army War College. Hershey taught military science at the Ohio State University and then served in the general staff as G-4 at the Department of Hawaii.
He was the longest-serving director in the history of the Selective Service System, and held the position until February 15 1970, spanning World War II, the Korean War and the Vietnam War.
In October 1967, in response to increasing demonstrations against military recruiting on college campuses, Hershey issued an order which became known as "The Hershey Directive," that anyone demonstrating against a military recruiter could be subject to immediate Selective Service reclassification of their draft status, meaning those students who demonstrated would be at risk of being immediately drafted. This order outraged students, many of whom were not subject to being drafted due to education deferments, and campus demonstrations against the war (and Hershey's order) increased.Hershey was removed from his Selective Service post by President Richard Nixon after becoming a focus of anti-war protests.
Nixon appointed him as a presidential adviser and promoted him to a full General - up to that time the only four-star General to reach that rank without having served in combat.
Hershey is a recipient of the prestigious Silver Buffalo Award from the Boy Scouts of America. He was a Scout leader and executive in Washington, DC. His previous awards from the Boy Scouts include the Silver Beaver Award and the Silver Antelope Award.