He joined the Army from Columbus Barracks, Ohio, and by May 11, 1889 was serving as a corporal in Company Bachelor of the 24th Infantry Regiment. On that day, he was among the troops attacked during the Wham Paymaster Robbery. After leaving the army in 1893, Mays worked as a laborer in Arizona and New Mexico.
He applied for a federal pension in 1922, but was denied.
He entered the Territorial Insane Asylum, now known as the Arizona State Hospital, in Phoenix, which housed not only the mentally ill but also people with tuberculosis and those living in poverty. He died at the hospital in 1925, at age sixty-seven, and was buried in the adjoining cemetery.
His grave was marked with only a small stone block, etched with a number. Eight years later, in March 2009 under the care of the Old Guard Riders Incorporated., Cpl Mays" remains were disinterred, cremated and placed in an urn designed especially for him.
On 29 May 2009, in a ceremony befitting a Medal of Honor recipient, Cpl Mays was interred in Arlington National Cemetery.