Dr. Giles reportedly received death threats and was asked to leave the institution due to the color of his skin, though he stayed and graduated with honors.

He passed the exam for Junior Physician at the Municipal Tuberculosis Sanitarium and at the Oak Forest Infirmary at the top of the Civil Service list; while certification was obtained eventually, his appointment was denied due to the color of his skin.

[9] Dr. Giles volunteered for service in the Medical Corps of the Army of the United States and entered as a Major, June 13, 1942.

He was promoted to Lieutenant Colonel in 1944 and became Chief of the Medical Services at the Thousand Bed Station and Regional Hospital in Fort Huachuca, Arizona.

Following World War II, he became a Lieutenant Colonel in the Organized Reserves of the U.S. Army until his death.