Canada had acquired those regions in 1870 and created the new Province of Manitoba, originally a square 18 times less its current size, as well as the new Northwest Territories, which by 1999 had ceded land to create today's Yukon and Nunavut Territories and the Provinces of Saskatchewan and Alberta, and ceded land to existing provinces' expansions into northern Ontario, northern Quebec, all of Manitoba, and the northeastern tip of British Columbia.
Canada acquired these regions in 1870, creating the Province of Manitoba, which was initially a much smaller square. The Northwest Territories then ceded land over time to create Yukon and Nunavut territories and the provinces of Saskatchewan and Alberta.  It also relinquished land for existing provinces' expansions into northern Ontario, northern Quebec, all of Manitoba, and the northeastern tip of British Columbia.