After quite a bit of searching, I found Sterling McCallum. He settled in Spokane, Washington and died there.
I think he probably married there, even though he married a girl from Nebraska. This is because the WWI draft schedule said he was 27 years old and single. In the 1920 census, though, he was married.
1910 Census in Genoa, Nance, Nebraska.
* He was living in the household of his mother, Mary McCallum. Their names were spelled McCullum.
* Mary McCallum is listed as a widow who had 5 children with 3 of them living.
* Also in the same household is Sterling's sister, Florence Mollin and her husband, Alfred Mollin, and son, Philip Mollin.
WWI Draft Record, 1917-1918
Draft record was in Spokane, Washington. Sterling is listed as single.
1920 Census, Spokane, Spokane, Washington
* Sterling M. McCallum
* Estella C. McCallulm, born in Nebraska.
Question? Because Estella was born in Nebraska.
1940 Census, Spokane, Spokane, Washington
* Sterling McCallum
* Estelle S. McCallum