The South Side is a major part of the city of Chicago, which is located in Cook County, Illinois. It is one of the three major parts of the city, the others being the West Side and the North Side. Much of it evolved from the city's incorporation of independent townships, such as Hyde Park Township, which voted along with several other townships to be annexed in the June 29, 1889 elections. Regions of the city, referred to as "sides," historically have been divided by the Chicago River and its branches.