According to his attestation papers dated April 14, 1915 at Hamilton, Harry Jackson as born on November 18, 1892 at Blackburn, England. He listed his mother M. Jackson, Manchester Street, Mimico as his next of kin. He was a labourer and an active member of the 36th Peel Regiment. He was 22 years and 6 months of age and stood 5 feet 6 1/2 inches tall. He had brown eyes, fair hair and complexion. He was Methodist.
His brother John also enlisted.
According to the 1911 census he was the son of Charles and Mary Jackson.