Alexander Jack was born on 9 January 1897 on Ferguson's Land in Dalmuir, County of Dunbarton. He was the oldest son of Alexander Jack and Jane Smallman, who were not married at the time of his birth. His father was a journeyman joiner, which did wood working and carpentry. In 1901 the family lived on One Brandon place in Dalmuir. Ten years later Alexander lived with his parents on Dumbarton Road in the town of Clydebank and worked as an machine assistant at the local shipyard.
He married Elizabeth Riddell on 30 August 1918 in Clydebank. He was 22 years old, lived at home with his parents and worked as an apprentice ship caulker. It is not known if the couple had children.
Alexander lost his wife, Elizabeth, in 1981, and he likely died the following year in Glasgow.
1901 Scotland Census, Parish: Old Kilpatrick; ED: 25; Page: 1; Line: 19; Roll: CSSCT1901_174
1911 Scotland Census, 02/04/1911 Jack, Alexander (Census 1911 501/00 026/00 003)
Scotland, Statutory Registrations, 1855-2013, 1897 Jack, Alexander (Statutory Births 501/00 0098)
Scotland, Statutory Registrations, 1855-2013, 1918 Jack, Alexander - Riddell, Elizabeth (Statutory Marriages 501/00 0228)
Scotland, Statutory Registrations Index, 1855-2013, 1982 Jack, Alexander (603/00 0810)