Cook County, Illinois in the context of "Daniel Pope Cook"

Chicago is the most populous city in the U.S. state of Illinois and in the Midwestern United States. Located on the western shore of Lake Michigan, it is the third-most populous city in the United States, with a population of 2.74 million at the 2020 census. The Chicago metropolitan area has 9.41 million residents and is the third-largest metropolitan area in the country. Chicago is the seat of Cook County, the second-most populous county in the U.S.

Chicago was incorporated as a city in 1837 near a portage between the Great Lakes and the Mississippi River watershed. It grew rapidly in the mid-19th century. In 1871, the Great Chicago Fire destroyed several square miles and left more than 100,000 homeless, but Chicago's population continued to grow. Chicago made noted contributions to urban planning and architecture, such as the Chicago School, the development of the City Beautiful movement, and the steel-framed skyscraper.

The Loop is Chicago's central business district and one of the city's 77 municipally recognized community areas. Located at the center of downtown Chicago on the shores of Lake Michigan, it is the second-largest business district in North America, after Midtown Manhattan in New York City. It contains the world headquarters and regional offices of several global and national businesses, retail establishments, restaurants, hotels, museums, theaters, and libraries—as well as many of Chicago's most famous attractions. The district also hosts Chicago's City Hall, the seat of Cook County, offices of the state of Illinois, United States federal offices, and several foreign consulates. The intersection of State Street and Madison Street in the Loop is the origin point for the address system on Chicago's street grid, a grid system that has been adopted by numerous cities worldwide.

The Loop's definition and perceived boundaries have evolved over time. Since the 1920s, the area bounded by the Chicago River to the west and north, Lake Michigan to the east, and Roosevelt Road to the south has been called the Loop. It took its name from a somewhat smaller area, the 35 city blocks bounded on the north by Lake Street, on the west by Wells Street, on the south by Van Buren Street, and on the east by Wabash Avenue—the Union Loop formed by the 'L' in the late 1800s. Similarly, the "South Loop" and the "West Loop" historically referred to areas within the Loop proper, but in the 21st century began to refer to the entire Near South and much of the Near West Sides of the city, respectively.

The City Hall-County Building, commonly known as City Hall, is a 12-story building in Chicago, Illinois, that houses the seats of government of the City of Chicago and Cook County. The building's west side (City Hall, 121 N. LaSalle St.) holds the offices of the mayor, city clerk, and city treasurer; some city departments; offices of alderpersons of Chicago's 50 wards; and the Chicago City Council's chambers. The building's east side (County Building, 118 N. Clark St.) houses offices of the Government of Cook County, including the Cook County Board of Commissioners' chambers.

The building spans a city block bounded by Randolph Street to the north, Washington Street to the south, Clark Street to the east, and LaSalle Street to the west. It is the seventh building to serve as Chicago's city hall, the fourth built at its location, and the third shared by the governments of Chicago and Cook County. Its location has served as the seat of the city and county governments since 1853, except for a period from 1871—when the Great Chicago Fire destroyed the building—to 1885.

There are 102 counties in Illinois. The most populous of these is Cook County, the second-most populous county in the United States and the home of Chicago, while the least populous is Hardin County. The largest by land area is McLean County, while the smallest is Putnam County. Illinois's FIPS state code is 17 and its postal abbreviation is IL.

What is now Illinois was claimed as part of Illinois County, Virginia, between 1778 and 1782. Modern-day county formation dates to 1790 when the area was part of the Northwest Territory; two counties — St. Clair and Knox — were created at that time. Knox would later become a county in Indiana and is unrelated to the current Knox County in Illinois, while St. Clair would become the oldest county in Illinois. Successive territorial governments created 15 counties by the time Illinois achieved statehood in 1818. The last county created in the state, Ford County, was created by the Illinois government in 1859.

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 resegregate.

Chicago State University (CSU) is a public university in Chicago, Illinois, United States.

Founded in 1867 as Cook County Normal School by the Cook County Board of Commissioners, it was established as the first teacher training school in Cook County. In 1949, when it was known as Chicago Teachers College, the institution was divided into two branches, with one eventually becoming Northeastern Illinois University. The state government of Illinois began funding the institution in 1951 and assumed full control in 1965. It was renamed the current name in 1971. CSU is a predominantly black (PBI) university. As of 2025, CSU had an 11 percent graduation rate within a four-year period of study.