Alexander married Frances Laura Forsyth 24 Mar 1913, Boston, Suffolk, Massachusetts, United States. Frances (daughter of Franklin James Forsyth and Frances A Porter) was born 21 Jun 1892, Bangor, Penobscot, Maine, United States; died Yes, date unknown. [Group Sheet]

1. L Shirley MacDonald was born CA 1914, , , Massachusetts, United States.
2. Robert Bruce MacDonald was born 1 Aug 1917, , , Massachusetts, United States; died 4 May 1997, Milton, , Massachusetts, United States.
3. John F MacDonald
4. Donald Francis MacDonald was born 18 Jul 1921, , , Massachusetts, United States; died 6 Jun 1988, East Wareham, Plymouth, Massachusetts, United States.
5. Walter MacDonald
6. Alexander MacDonald, Jr