Withrow had an official U.S. post office from 1890 to 1963, and a rural branch office from 1963 to 1966. The post office opened on June 11, 1890, in the rear of the B. W. Ellis general store; Ellis was the postmaster. In 1909 fire destroyed the store, and stamps and documents pertaining to the U.S. postal service were lost. After the fire, Clarence LeRoy Kinyon, who had been the mail carrier, reopened the store and post office, selling hardware, groceries, fabric, and clothing. The post office relocated to the former Withrow State Bank building in the mid- to late 1940s, and relocated again to the former Kinyon house, which had been purchased by William and Vivian Guse, in 1950; the post office was moved to the porch of the house, where residents could pick up mail from their P.O. boxes, buy stamps, and mail packages. Vivian Guse was the postmistress until 1966. The mail pouch was brought to the train depot daily and hung on the mail hook, where it was picked up by a passing train. In 1962 the Guses opened the Withrow Tavern and a small grocery store selling Gulf gasoline in the old creamery building, locating the post office there until mail delivery was taken over by rural route carrier. The Kinyon general store building was destroyed by fire in 1981.
