Duncan married Isabella Montgomery on 14 Mar 1870 in Cornwall, Stormont, Ontario, Canada. Isabella (daughter of Donald Daniel Montgomery and Jane Shea) was born in 1846 in Strathmore, Roxborough, Stormont, Ontario, Canada. [Group Sheet] [Family Chart]

1. Isabella Jane Mcintosh was born in 1872 in Of Oro Twp, Penetanguishene, Ontario.
2. Alex Cougar Mcintosh was born in 1875 in Of Oro Twp, Penetanguishene, Ontario.
3. John Henry Mcintosh was born in 1878 in Of Oro Twp, Penetanguishene, Ontario.
4. Catherine Ann Mcintosh was born in 1880 in Of Oro Twp, Penetanguishene, Ontario.