The Chicago metropolitan area, also colloquially referred to as Chicagoland, is a metropolitan area in the Midwestern United States. Encompassing 10,286 sq mi (28,120 km2), the metropolitan area includes the city of Chicago, its suburbs and hinterland, spanning 14 counties in northeast Illinois, northwest Indiana, and southeast Wisconsin. The MSA had a 2020 census population of 9,618,502 and the combined statistical area which spans up to 19 counties had a population of nearly 10 million people. The Chicago area is the fourth largest metropolitan area in North America (after the metro areas of Mexico City, New York City, and Los Angeles), the third-largest metropolitan area in the United States, the largest within the entire Midwest, and the largest in the Great Lakes megalopolis. Its urban area is one of the forty largest in the world. According to the 2020 Census, the metropolitan's population is approaching the 10 million mark. The metropolitan area has seen a substantial increase of Latin American residents on top of its already large Latin population, and the Asian American population also increased according to the 2020 Census. The metro area also has a large number of White, Black, and Arab American residents, making the Chicago metropolitan area a truly diverse region. The Chicago metropolitan area represents about 3 percent of the entire United States population. Chicagoland, as the metropolitan area is also called, has one of the world's largest and most diversified economies. With more than six million full and part-time employees, the Chicago metropolitan area is a key factor of the Illinois economy, as the state has an annual GDP of over $1 trillion. The Chicago metropolitan area generated an annual gross regional product (GRP) of approximately $700 billion in 2018. The region is home to more than 400 major corporate headquarters, including 31 in the Fortune 500 such as McDonald's, Boeing, United, and Blue Cross Blue Shield. With many companies moving to Chicagoland, and many current companies expanding, the area ranked as the nation's top metropolitan area for corporation relocations and expansions for nine consecutive years, the most consecutive years for any region in the country. The Chicago area is home to a number of the nation's leading research universities including the University of Chicago, Northwestern University, University of Illinois at Chicago, DePaul University, Loyola University, and the Illinois Institute of Technology. The University of Chicago and Northwestern University are consistently ranked as two of the best universities in the world. There are many transportation options around the area. The region has three separate rail networks: the Chicago Transit Authority (CTA) operates elevated and subway lines that run primarily throughout the city, Downtown Chicago, and into some suburbs. The CTA operates some rail lines 24 hours a day, every day of the year, nonstop service, making Chicago and New York City the only two cities in the world to offer some 24 hour rail service running nonstop, everyday throughout their city limits. The city-suburban Metra rail network runs numerous lines between Downtown Chicago and suburban/satellite cities. And the South Shore Line runs between Downtown Chicago and suburban Northwest Indiana. Amtrak operates a national rail hub at Union Station in Downtown Chicago. CTA bus routes primarily serve the city proper, with some service into the suburbs. Several CTA bus routes also operate 24 hours a day, nonstop. Pace bus routes primarily serve the suburbs, with some service into the city. From Wikipedia
