He was the son of James Walker and Annie Mary Walker. In 1901 the family are living in house 1, Ballyrock Scotch, Beardiville, Co. Antrim. By 1911 the property is recorded as house 5, Ballyrock Scotch, Beardiville, Co. Antrim.
In 1911, Walker is boarding in house 1.2 Castlewood Avenue, Rathmines & Rathgar East, Co. Dublin. He is described as a Bank Clerk. There are a further 2 possible colleagues boarding; Samuel H Eakin (22) and Archibald A Ennes (20), both described as Bank Clerks.
The Belfast Banking Company 'Roll of Honour' booklet records Walker as having been 'previously wounded' with his last known address 'Palestine'.
The National Archives records a Medal Index Card as follows:
Royal Inniskilling Fusiliers, 2nd Lieutenant
Royal Inniskilling Fusiliers, Lieutenant