John enlisted on 3rd December 1906. He was 19 years and 8 months old at the time. He entered the war in France on 16th August 1914 as part of the Regimental Medical Officer's team for the Army Troop Train. On 20th May 1915 he joined Base Details, after serving 21 days of field punishment for drunkenness. He was posted to serve with No 2 Ambulance Flotilla on 1st June 1915. After a couple of bouts of illness from 29th September 1916, he was evacuated back to England on 17th October 1917. He was discharged "no longer physically fit for war service" on 17th November 1917, suffering from tuberculoses of the lung. He was the son of Thomas and Emily Jackson of 71 Francis Street, Middlesbrough.