According to his attestation papers dated May 15, 1916 at Toronto, John Jackson of Manchester Street, Mimico was born on July 31, 1896 at Blackburn, Lancashire, England. He listed his mother Mary Jackson, Manchester Street, Mimico as his next of kin. He was a labourer and had no previous military experience. He was 19 years and 11 months of age and stood 5 feet 6 inches tall. He had brown eyes, auburn hair and a fair complexion. He had a scar on his left thigh and a mole on the right side of his nose.
His brother Harry also enlisted.
According to the 1911 census he was the son of Charles and Mary Jackson.
According to the 1914 Toronto City directory he was a labourer living on the south side of Symons Street.