Wayne County, where the city of Detroit is located, borders Oakland County to the south. 8 Mile Road, also known as "Baseline Road" in some areas, is the boundary between these counties. The baseline was used during the original surveying for Michigan, and it serves as the northern/southern boundaries for counties from Lake St. Clair to Lake Michigan. As more working and middle-class populations moved to the suburbs from the 1950s on, this divide (8 Mile Road) became historically known as an unofficial racial dividing line between what became the predominantly black city and almost exclusively white suburbs.