Level 6 of the Central Library has a collection of illustrated historical county atlases covering much of Ontario, as well as parts of Quebec and the Maritime provinces. These atlases contain a great deal of information of interest to genealogists.
The idea of county atlases originated in the United States, where about 500 county atlases were produced between 1864-1875. In due course, a few enterprising publishers sought a new market in Canada. From 1875-1881, thirty-two atlases were published covering forty Ontario counties. Only Haliburton, Peterborough and Leeds & Grenville counties were not covered. There was also no atlas produced for Dufferin, since the county was not constituted until 1879. Information relating to what became the Dufferin area is included in atlases for three adjacent counties.