The former Township of McNab lies in the southeastern corner of Renfrew County and is one of the earliest settled regions in the Ottawa Valley. Surveyed in the 1820s, McNab was settled under the direction of Archibald McNab, the 13th Laird of McNab, who attempted to recreate a Scottish feudal estate by imposing rents and obligations on arriving settlers. His practices caused decades of legal disputes, eventually resolved in favour of the settlers by the 1850s.

The township benefited from fertile soils and proximity to the Ottawa River, supporting both agriculture and early industry. Several communities developed within its bounds, including Burnstown and White Lake.

Land surveyors in McNab often encounter historical complexities stemming from the lairdship disputes—title chains may reflect pre-patent leases, private surveys, and overlapping rights. The grid system is generally intact, but some early land allocations deviated from standard protocols, requiring thorough research through both Crown and local archives.