Duncan married Diana Montgomery on 2 Feb 1826 in Cornwall, Stormont, Ontario, Canada. Diana (daughter of John Montgomery and Susannah Lillie) was born on 1 Jan 1809 in Roxborough, Stormont, Ontario, Canada; died in Bruce, Ontario, Canada. [Group Sheet] [Family Chart]

1. Christie Ann McCallum was born in 1827 in Strathmore, Roxborough, Stormont, Ontario, Canada.
2. John McCallum was born on 21 Mar 1829 in Strathmore, Roxborough, Stormont, Ontario, Canada; died on 31 Aug 1902 in Greenwood, Sebastian, Arkansas.
3. Duncan R. McCallum was born in 1830 in Strathmore, Roxborough, Stormont, Ontario, Canada.
4. Susanna McCallum was born on 8 Jan 1833 in Strathmore, Roxborough, Stormont, Ontario, Canada; died on 8 Feb 1919 in Paisley, , Ontario, Canada.
5. William McCallum was born in 1834 in Strathmore, Roxborough, Stormont, Ontario, Canada.