Contained within the 3rd Edition (1957) of the Atlas of Canada is a plate that shows the distribution of population in what is now Canada circa 1851, 1871, 1901, 1921 and 1941. The five maps display the boundaries of the various colonies, provinces and territories for each date. Also shown on these five maps are the locations of principal cities and settlements. These places are shown on all of the maps for reference purposes even though they may not have been in existence in the earlier years. Each map is accompanied by a pie chart providing the percentage distribution of Canadian population by province and territory corresponding to the date the map is based on. It should be noted that the pie chart entitled Percentage Distribution of Total Population, 1851, refers to the whole of what was then British North America. The name Canada in this chart refers to the province of Canada which entered confederation in 1867 as Ontario and Quebec. The other pie charts, however, show only percentage distribution of population in what was Canada at the date indicated. Three additional graphs are included on this plate and show changes in the distribution of the population of Canada from 1867 to 1951, changes in the percentage distribution of the population of Canada by provinces and territories from 1867 to 1951 and elements in the growth of the population of Canada for each ten-year period from 1891 to 1951.

Contained within the 3rd Edition (1957) of the Atlas of Canada is a map that shows the distribution of the Canadian population, circa 1951. Population sizes are indicated on the map by representative units of 50 or 1000. In southern Canada, the population of the 15 metropolitan areas and urban centres of 25 000 inhabitants and over is shown by a disc, the area of which is proportional to its population. The scale ranges from metropolitan Montreal (1 395 400 inhabitants) to Glace Bay (25 586 inhabitants). There are still very small populations in northern Canada, but there are clusters within Capital cities, and a even larger concentration south, near the U.S. border, in particular along ocean or inland coastlines. The congregation near or on the coastline of water indicate the influence of industry, natural resources and trade. Two graphs accompany this map. The first graph shows the numerical distribution of population for 1951 by Canada, the provinces and the territories. The second graph shows the percentage distribution of population for 1951 by province and territory.