Why was Upper Canada renamed Canada West in 1841?

Upper Canada was renamed Canada West in 1841 following the union of Upper and Lower Canada into the single Province of Canada.12

This political reorganization was a direct response to the abortive rebellions of 1837–38, which highlighted the instability and constitutional limitations of the existing colonial governments. Following an inquiry into these disturbances, John George Lambton, 1st earl of Durham, recommended the reunion of the two colonies to foster economic growth, improve administration, and promote the assimilation of the French-speaking population.23

By uniting the two regions, the British government sought to create a more effective and unified administration. Although the name "Canada West" was adopted for the region formerly known as Upper Canada, the terms Upper Canada and Canada West were often used interchangeably during this period. This union remained in effect until the British North America Act of 1867, which established the Dominion of Canada and reorganized the territory into the provinces of Ontario and Quebec.12