Litherland Camp was a demobilization centre for the North West at the end of The Great War 1914-1918.
40769 Pte Joseph John Smith, The King's Own Yorkshire Light Infantry. He crossed to France in 1915 with the 9th Battalion KOYLI.
Discharged and went into the Z Reserve 10/12/1919.
Amazing what can be found on the Tinternet just by the info on the envelope.