Located at the confluence of the Mississippi and Minnesota rivers, Minneapolis and St. Paul, Minnesota, once heated rivals, are known today as the Twin Cities and are the nexus of a thriving 11-county metropolitan area. Home to the largest of the four campuses of the University of Minnesota, the area has rich cultural resources and a reputation for civic involvement by ordinary citizens and by its business community. It is home to numerous major corporations, which draw on a well-educated labor pool. In the decades since World War II (1939–45), the region's population has become increasingly a suburban one, but urban redevelopment has kept its central cities vital and safe.