Ditter, a Republican, was elected to Congress from the 17th District of Pennsylvania in 1932, and during his years in Washington served on the House Committee on Appropriations. He also was a member of the subcommittee on Navy Department appropriation bills, and at the time of his death was ranking minority member.
Congressman Ditter was a supporter of a strong Navy and vitally interested in its welfare. He was killed in an airplane crash near Lancaster, Pennsylvania on 21 November 1943.