Chicago’s population history reflects its rapid growth and remarkable diversity. Founded in 1833 with fewer than 200 settlers, the city grew to over 4,000 by 1840 and expanded to more than 1 million residents by 1890, making it the second-most populous U.S. city at the time. By 1900, it was the fifth-largest city in the world, and its population peaked at 3.6 million in 1950. Over the latter half of the 20th century, the population declined, reaching under 2.7 million in 2010, before rising slightly to 2.74 million in 2020 and an estimated 2.72 million in 2024.

Chicago’s demographic makeup has been shaped by successive waves of migration and immigration. In the late 19th and early 20th centuries, European immigrants—including Italians, Poles, Jews, Greeks, Armenians, and others—formed the backbone of the city’s industrial workforce. Simultaneously, African Americans arrived from the American South during the Great Migration, with Chicago’s Black population doubling between 1910 and 1920, and again by 1930. Many settled in the South Side “Black Belt” and parts of the West Side, making Chicago home to the nation’s second-largest urban black concentration after New York’s Harlem.

In recent decades, demographic shifts have continued. There has been a migration of African Americans to suburban areas, driven by crime rates and cost-of-living considerations. Chicago also has a significant foreign-born population, particularly from Mexico, Poland, and India. The city hosts one of the largest Jewish populations in the U.S., estimated at over 319,000 in the metropolitan area. As of 2019, Chicago’s largest racial and ethnic groups are non-Hispanic Whites (32.8%), Blacks (30.1%), and Hispanics (29.0%), highlighting its continued status as a diverse, multicultural metropolis.

Over nearly two centuries, Chicago has evolved from a frontier settlement to a global city defined by its dynamic population, cultural richness, and ongoing social transformations.