Chicago Map
At the southwestern corner of Lake Michigan, Chicago had about 2.72 million residents in 2024 and remains the largest city between the Appalachians and the Rockies.
Where is Chicago?
Chicago is in the far northeastern corner of Illinois, pressed against the Indiana line and running some 26 miles along the Lake Michigan shore. The land behind it is flat enough that the city spread almost unbroken across the prairie. It sits about 90 miles south of Milwaukee, roughly 185 miles northwest of Indianapolis, and about 280 miles west of Detroit.
Chicago at a glance
| State | Illinois |
| Counties | Cook, and DuPage counties |
| Population | 2,721,308 (2024 Census estimate) |
| Rank among US cities | No. 3 of the 100 largest |
| Time zone | Central Time |
| Region | Midwest (East North Central division) |
Chicago sits at No. 3 in the 2024 estimates, 1,157,396 people behind Los Angeles and 331,183 ahead of Houston. No second Illinois city reaches the hundred. One city government therefore accounts for about 21% of Illinois's 12.71 million people. It reaches into two counties, of which Cook County is much the largest: the city holds about 53% of that county's 5,182,617 people.
Chicago in Illinois
Almost every large Illinois city outside the Chicago area is a fraction of its size; the state capital, Springfield, is about 200 miles southwest. Chicago fills most of Cook County and spills west into DuPage County, both of which appear on the Illinois county map. The Illinois state page shows how heavily the state's population leans into this one corner, while Milwaukee and Indianapolis are the nearest large cities across state lines.
The portage that made the city
Chicago exists because of a low, swampy divide a few miles west of the lake. On one side, water drains into Lake Michigan and the Great Lakes; on the other, into the Des Plaines and Illinois rivers and eventually the Mississippi. Canoes were carried across that gap for centuries, canals later cut through it, and in 1900 engineers reversed the Chicago River so that the city's sewage flowed away from its drinking water and down toward the Mississippi instead. The shoreline itself is largely made ground, built out into the lake.
Cities near Chicago
Around the southern lake are Milwaukee and Indianapolis; further out sit Detroit, St. Louis and Minneapolis. The Midwest region page puts them all in order.