Walter was the son of George and Alice McMullin of ‘Oaklyn’ Ashford. His birth was registered at Inverell in 1893. He was a twenty two year old Labourer when he enlisted in August 1915 at Warwick Farm NSW. Before leaving the district he was one of several recruits farewelled by the Mayor of Inverell who, on behalf of Ashford friends, presented him with a fountain pen.
He became a member of the 1st Light Horse Regiment, 11th Reinforcement which sailed from Australia on HMAT A47 Mashobra in October 1915.
Walter served in Egypt until going to France in mid June 1916. He was promoted from Gunner to Bombardier with the 10th Field Artillery Brigade. Walter was wounded and subsequently died of his injuries on 6 August 1917. His burial took place at Aeroplane Cemetery, Belgium. Some of his personal effects returned to his family included a diary, tobacco pouch, wrist watch and strap, fountain pen and collar badge.