Projection: Lambert Conformal Conic
From http://ccri.library.ualberta.ca/enindex.html: The CCRI represents an infrastructure that facilitates research on the transformation of Canadian society in the twentieth century. The CCRI's mandate is to provide researchers with a body of data and information that can be used to acquire a better understanding of how modern-day Canada has developed. The CCRI is composed of microdata, namely, data created from Canadian census enumerations between 1911 to 1951, a geographical framework constructed to enable the location, selection, aggregation, and analysis of census data, and contextual data, namely the textual data used to situate the census in time and to enhance appropriate analysis of the data.
Shapefiles representing the census divisions (CDs) and census subdivisions (CSDs) in use across Canada in 1911, 1921, 1931, 1941, and 1951 are available for download.
While the project is now hosted at the University of Alberta, more information about the CCRI is available on an archived site at the University of Ottawa: http://www.canada.uottawa.ca/ccri/CCRI/Home.html