Rex Bixby spent two years in the Army National Guard before he enlisted in the regular army in 1917. He was sent to Texas to train as a pilot at the School of Military Aeronautics. Though he did not serve overseas, the early days of aviation were fraught with danger. According to the newspaper accounts pasted into a scrapbook he kept, Bixby was injured in a crash and one of his fellow pilots was killed during a training mission. Like all soldiers, Bixby's personal identity tags or "dog tags" ensured that he could be identified and loved ones notified in the event he was wounded or died in service.