John Sinclair was born in 1808, Bowmore Parish, Islay, the son of Neil Sinclair and Christian Campbell.

He married Emma Hamilton Campbell in 1833, and they emigrated to Canada the following year, just after the birth of their first son, Neil. They spent their first few years in the Toronto area, becoming embroiled in the Rebellion of 1837, when John became a "wanted man". They eventually settled at Cambray, Victoria County, Ontario, where their family grew and prospered.

Emma Hamilton Campbell Sinclair, also born in Bowmore Parish, in 1810, daughter of John Campbell and Mary McVoran, but she became an orphan as a young child.

Children: Neil 1834, John 1838, Christian 1841, Donald 1843, Alexander 1844, Mary 1847, Dougal 1851, Catherine 1853, William 1857.

John and Emma both died in 1888.