Samuel McKeown was the son of James and Mary Jane McKeown. He was born on 5th June 1884. He was one of at least eight children, all born in the Coagh area. The family lived at Crumlin Cottage, Coagh. His father was a farmer and an accountant. On leaving school he joined the civil service and worked in London County Council. After the war started, he enlisted in the Oxfordshire and Buckinghamshire Light Infantry, and was given the rank of sergeant from the date of enlistment. He was put on the supplementary list of the General Reserve of Officers, which meant he was seconded out as necessary. 2nd Lieutenant Samuel McKeown went on to serve with the 14th Battalion of the Worcestershire Regiment.