On-15 July 1870 all of Canada between Lake Superior and the Rocky Mountains was under the control of the Hudson’s Bay Company. On that date Canada assumed control of the area, established Manitoba in the eastern section, and the remainder as the North West Territories. On 8 May 1882 the southern section of the North West Territories was further divided into four postal districts – Assiniboia, Saskatchewan, Alberta and Athabasca. On 1 September 1905 the District of Assiniboia, comprising about 95,000 square miles, was absorbed into the new Provinces of Alberta and Saskatchewan, most of it in Saskatchewan. The remainder became part of Alberta.
After describing its development, mainly through the expansion of the railways, “The Postal History of the District of Assiniboia 1822-1905” lists all the towns of the District in alphabetical order, giving the location on a grid map, opening and closing dates of the office, population and general information, names of postmasters with their terms, types of postmarks and known handstamps.