Duncan married Mary BLAIR about 1851. Mary (daughter of Robert BLAIR and Margaret WRATH) was born on 16 Feb 1827 in Coleraine Co., Londonderry, Ireland; died on 2 Jul 1914 in Cobden, Renfrew, Ontario, Canada; was buried in Cobden, Renfrew, Ontario, Canada. [Group Sheet] [Family Chart]

1. Peter Donald MCMARTIN was born in 1852 in Ross Twp., Renfrew, Ontario, Canada; died on 18 Feb 1924 in Brandon, Westman, Manitoba, Canada; was buried in Minnedosa, Manitoba, Canada.
2. Esther Supple MCMARTIN was born on 24 Apr 1854 in Ross Twp., Renfrew, Ontario, Canada; died on 27 Feb 1897 in Ross Twp., Renfrew, Ontario, Canada; was buried in Ross Twp., Renfrew, Ontario, Canada.
3. Duncan MCMARTIN was born on 25 Jan 1857 in Ross Twp., Renfrew, Ontario, Canada; died on 20 Jul 1941 in Franklin, , Manitoba, Canada.
4. Edward MCMARTIN was born on 17 Jul 1859 in , Renfrew, Ontario, Canada; died on 24 Apr 1933 in Dauphin, Dauphin, Manitoba, Canada; was buried in Dauphin, Dauphin, Manitoba, Canada.