During World War II, McDonald served overseas as a Flight Lieutenant in the Royal Canadian Air Force.
Upon returning from the Second World War with his wife, the former Madeleine Anne Casey of Washington, D.C., McDonald went back to the 960-acre (3.9 km2) Fleming farm originally settled by his grandfather in 1881.
An article[publisher missing][citation needed] describing his career in this context noted, "The swift and dazzling rise of 37-year-old Alexander Hamilton McDonald to the leadership of the Liberal Party in Saskatchewan has no parallel in Canadian political history."
He took part in community activities as a member of the Royal Canadian Legion, the United Services Institute and the Elks Lodge.
His funeral – held at the United Church in Moosomin, Saskatchewan – was overflowing with dignitaries from Ottawa, the provinces and many, many locals from within the constituency.