Duncan married Mary ECKFORD in 1852 in , Renfrew Co., Ontario, Canada. Mary (daughter of James ECKFORD and Helen Ellen GLENDINNING) was born in 1830 in , , , Scotland; died in 1905 in , Renfrew Co., Ontario, Canada; was buried in Goshen Public Cemetery, Renfrew Co.., Ontario. [Group Sheet] [Family Chart]

1. Donald MCMILLAN was born in McNab Twp., Renfrew, Ontario, Canada; and died.
2. Peter MCMILLAN was born in 1868 in McNab Twp., Renfrew, Ontario, Canada; died on 15 Sep 1936 in Renfrew, Renfrew, Ontario, Canada; was buried in Goshen Public Cemetery, Renfrew Co.., Ontario.