[1] Parker enlisted for World War I, was commissioned as a second lieutenant in the Ordnance Corps, and served in the aerial armament field at posts including Camp Devens, Massachusetts, and Selfridge Field, Michigan until receiving his discharge in October 1919.
[1][2] Upon returning to Vermont, Parker resumed his career as a teacher and principal, and also studied law in the Hartford office of attorney Raymond J.
[3] In 1940, Parker was the successful Republican nominee for Vermont Attorney General.
[5] After serving as attorney general, Parker resumed practicing law.
[7] Parker was the father of three children, daughters Harriet Ann and Judith, and son Richard Henry.