872 Area Code 🌍☎️

Chicago is the third-most populous city in the United States with 2.74 million residents at the 2020 census, located on the western shore of Lake Michigan in Illinois, and serves as the seat of Cook County, the second-most populous county in the U.S. Incorporated as a city in 1837 near a portage between the Great Lakes and Mississippi River watershed, Chicago experienced rapid growth in the mid-19th century and rebuilt after the devastating 1871 Great Chicago Fire, becoming a leader in urban planning and architecture including the Chicago School and steel-framed skyscraper development. As an international hub for finance, culture, commerce, and transportation, Chicago hosts the world's largest and most diverse finance derivatives market generating 20% of all commodities and financial futures volume, O'Hare International Airport among the world's busiest airports, and a metropolitan economy ranking sixth globally with over $919 billion in GDP in 2024. The city attracts 55 million annual visitors to its cultural institutions, Lake Michigan beaches, and restaurants, while contributing significantly to jazz, blues, house music, and improvisational comedy through venues like the Chicago Symphony Orchestra, Lyric Opera, and Art Institute of Chicago. Chicago hosts major professional sports teams across all major leagues, the renowned Chicago Marathon, and prestigious universities including the University of Chicago and Northwestern University, solidifying its status as a global cultural and economic center.