John Gorham Chandler was born around 1830 in Massachusetts. He enrolled at West Point in 1848 and graduated on July 1, 1853. He received an appointment as a 2nd lieutenant in the 3rd United States Artillery, and he spent the next few years stationed in California, Oregon. He was promoted to 1st lieutenant on May 31, 1856, and to captain on May 17, 1861.
He served as an assistant quartermaster during the Civil War. He took part in the Battle of Shiloh, the Battle of Perryville, and the siege of Port Hudson. On November 17, 1862, he was promoted to chief quartermaster of the 19th Army Corps with the rank of lieutenant colonel. He later received a brevet promotion to colonel.
He remained in the army after the war, serving as quartermaster in New Orleans, Louisiana. Army officials transferred him to the Department of Dakota in 1866, and he was promoted to major on January 18, 1867. He was stationed at Fort Leavenworth, Kansas, from 1872 until 1874, then in the Department of Arizona until 1876 and the Department of the South until 1881. He was promoted to lieutenant colonel on March 4, 1879, and he served as assistant to the Quartermaster-General from 1881 until 1888. He retired on December 31, 1894.
He married a woman named Louise around 1890, and they settled in Los Angeles, California, after he left the army. His wife died around 1901, and he passed away in Los Angeles on June 20, 1915.