On August 15, 1917, he was appointed a first lieutenant in the United States Army and served in France during World War I as captain of Battery B, Forty-sixth Artillery Corps, later being in command of the Third Battalion of his regiment. Following the Armistice, he was on detached service with the American Relief Administration under Herbert Hoover in 1919.
Career
After his discharge, Hollister resumed his law practice in Cincinnati. He served as director of various financial and manufacturing corporations, and was a member of the Cincinnati Board of Education from 1921 to 1929.
Congress
Hollister was elected as a Republican to the Seventy-second Congress in a special election held on November 3, 1931, to fill the vacancy created by the death of Nicholas Longworth. He was reelected to the two succeeding Congresses and served from November 3, 1931, to January 3, 1937. He was defeated for reelection in 1936 and resumed the practice of law.
He returned to Cincinnati, where he died on January 4, 1979, at the age of 88. His remains were cremated and the ashes interred in Spring Grove Cemetery.