Oak Park is a village in Cook County, Illinois, United States, adjacent to Chicago. It is the 26th-most populous municipality in Illinois, with a population of 54,318 as of the 2020 census. Oak Park was first settled in 1835 and later incorporated in 1902, when it separated from Cicero. It is closely tied to the smaller town of River Forest sharing a chamber of commerce and a high school, Oak Park and River Forest High School. Architect Frank Lloyd Wright and his wife settled in Oak Park in 1889, and his work heavily influenced local architecture and design, including the Frank Lloyd Wright Home and Studio. Over the years, rapid development was spurred by railroads and streetcars connecting the village to jobs in nearby Chicago. In 1968, Oak Park passed the Open Housing Ordinance, which helped devise strategies to integrate the village rather than re-segregate. Today, Oak Park remains ethnically diverse, and is known for its socially liberal politics, with 80% or higher voter turnout in every presidential election since 2000. Oak Park has several public transportation links to Chicago with Chicago Transit Authority access via the Green Line and Blue Line "L" train lines, as well as the Metra Union Pacific West Line Oak Park station downtown.