Source: April 1918 war diary. Taken on strength April 26, 1918.
Family Search: When Lieutenant John Alexander Alister MacMillan was born on 11 November 1892, in Hamilton, Ontario, Canada, his father, Roderick McMillan, was 42 and his mother, Sarah Baldwin, was 37. He married Ella Douglas Rose on 20 November 1913, in Hamilton, Hamilton-Wentworth, Ontario, Canada. He lived in Stormont Dundas and Glengarry, Ontario, Canada in 1901 and Hamilton, Hamilton-Wentworth, Ontario, Canada in 1911. He registered for military service in 1917. In 1958, at the age of 66, his occupation is listed as superintendent, massey-harris-ferguson in Ontario, Canada. He died on 17 October 1959, in Grimsby, Lincoln, Ontario, Canada, at the age of 66, and was buried in Queen’s Lawn Cemetery, Grimsby, Niagara, Ontario, Canada.
LAC record indicates he had an alias as John ALEXANDER MacMillan.
History of the 18th Battalion CEF, "The Fighting Eighteenth" 