After 1850, Cook County was divided into townships, which administered basic governmental functions. Residents who wanted more than basic services could petition the Illinois legislature for incorporation as a village, town, or city with more extensive powers to provide services and tax local residents. Laid out in 1830, Chicago incorporated as a city in 1837, and by the 1870s all of the townships surrounding the city had also incorporated. Beyond the ring of incorporated townships, parts of townships also sought incorporation by the 1880s. For Chicago, the period of extensive annexations extended from 1851 to 1920. The largest annexation occurred in 1889, when four of five incorporated townships surrounding Chicago (as well as a part of the fifth) were annexed to the city. Most annexations to Chicago during these years came because Chicago offered superior services, from better water connections in the nineteenth century to better high schools in the early twentieth. Later, prior incorporations and suburban resistance to the power and urban complexity of Chicago halted the process.

Author: Ann Durkin Keating (Research assistance: Dennis McClendon)
Source: Newberry Library