Editing Oshawa (section)

===Post-war===
{{Unreferencedsect|date=March 2025}}
In 1950, the city annexed a portion of East Whitby Township west of Park Road. Some of this area had been developed during the 1920s boom period, although it was not within the boundaries of the city. The opening of the Oshawa Shopping Centre (now the [[Oshawa Centre]]) fewer than two kilometres west of the "four corners" in 1956 struck a blow to Oshawa's downtown from which it has never been able to recover. The shopping centre was built on land which had been an unproductive farm; when its owner gave up on agriculture, this released a very large area of land for the construction of a mall. The opening of what later became [[Ontario Highway 401|Highway 401]], then known as Highway 2A, shortly after World War II sparked increased residential growth in Oshawa and the other lakeshore municipalities of Ontario County, which led to the creation of the Regional Municipality of Durham in 1974. Oshawa was amalgamated with the remaining portions of East Whitby Township and took on its present boundaries, which included the outlying villages of Columbus, Raglan and Kedron. Much of Oshawa's industry has closed over the years; however, it is still the headquarters of GM Canada and its major manufacturing site. Current industries of note include manufacturing of railway maintenance equipment, mining equipment, steel fabrication, and rubber products. Oshawa is also recognized as an official port of entry for immigration and customs services.