According to his WWI draft registration he was badly crippled with arthritis and unable to perform manual labor.
From The Hawarden Independent, June 20, 1957: William Barnum, 72, long time Hawarden resident, died at the Hawarden hospital early Wednesday (June 19) morning where he had been a patient five days. He had been ill with a heart ailment many months. Mr. Barnum was born April 1, 1885, at Mount Ida, Wis. As a child he moved west with his parents and settled at Hawarden. On July 27, 1913, he married Elena Carlson of Huron, S. D., at Hawarden, where the couple made their home. He was a railroad employee. Survivors include a daughter, Mrs. Florence Johnson of Farnhamville, lowa; a son, William F. Jr., of Hawarden; four sisters, Mrs. Adella Everett of Kirkland, Wash., Mrs. Grace Bedard of Sioux Fails, Mrs. Ethel Hout of Hawarden and Mrs. Ella Querles (sic Quarles) of Deer Lodge, Mont.; a brother, Eldon Barnum of Sioux Falls, and six grandsons.
Funeral services will be held at 2 o'clock Friday afternoon at the Barnard Funeral home with Rev. Paul Williams in charge. Interment will be at Grace Hill Cemetery.