Chicago (/ʃɪˈkɑːɡoʊ/ (listen), locally also /ʃɪˈkɔːɡoʊ/), officially the City of Chicago, is the most populous city in the U.S. state of Illinois and the third most populous city in the United States. With an estimated population of 2,705,994 (2018), it is also the most populous city in the Midwestern United States. Chicago is the county seat of Cook County, the second most populous county in the US, with portions of the northwest side of the city extending into DuPage County near O’Hare Airport. Chicago is the principal city of the Chicago metropolitan area, often referred to as Chicagoland. At nearly 10 million people, the metropolitan area is the third most populous in the nation.
Chicago is located in northeastern Illinois on the southwestern shores of freshwater Lake Michigan. It is the principal city in the Chicago metropolitan area, situated in both the Midwestern United States and the Great Lakes region. The city rests on a continental divide at the site of the Chicago Portage, connecting the Mississippi River and the Great Lakes watersheds. In addition to it lying beside Lake Michigan, two rivers—the Chicago River in downtown and the Calumet River in the industrial far South Side—flow either entirely or partially through the city.
Chicago’s history and economy are closely tied to its proximity to Lake Michigan. While the Chicago River historically handled much of the region’s waterborne cargo, today’s huge lake freighters use the city’s Lake Calumet Harbor on the South Side. The lake also provides another positive effect: moderating Chicago’s climate, making waterfront neighborhoods slightly warmer in winter and cooler in summer.
When Chicago was founded in 1837, most of the early building was around the mouth of the Chicago River, as can be seen on a map of the city’s original 58 blocks. The overall grade of the city’s central, built-up areas is relatively consistent with the natural flatness of its overall natural geography, generally exhibiting only slight differentiation otherwise. The average land elevation is 579 ft (176.5 m) above sea level. While measurements vary somewhat, the lowest points are along the lake shore at 578 ft (176.2 m), while the highest point, at 672 ft (205 m), is the morainal ridge of Blue Island in the city’s far south side.
While the Chicago Loop is the central business district, Chicago is also a city of neighborhoods. Lake Shore Drive runs adjacent to a large portion of Chicago’s waterfront. Some of the parks along the waterfront include Lincoln Park, Grant Park, Burnham Park, and Jackson Park. There are twenty-four public beaches across 26 miles (42 km) of the waterfront. Landfill extends into portions of the lake providing space for Navy Pier, Northerly Island, the Museum Campus, and large portions of the McCormick Place Convention Center. Most of the city’s high-rise commercial and residential buildings are close to the waterfront.
An informal name for the entire Chicago metropolitan area is “Chicagoland”, which generally means the city and all its suburbs. The Chicago Tribune, which coined the term, includes the city of Chicago, the rest of Cook County, and eight nearby Illinois counties: Lake, McHenry, DuPage, Kane, Kendall, Grundy, Will and Kankakee, and three counties in Indiana: Lake, Porter and LaPorte. The Illinois Department of Tourism defines Chicagoland as Cook County without the city of Chicago, and only Lake, DuPage, Kane, and Will counties. The Chicagoland Chamber of Commerce defines it as all of Cook and DuPage, Kane, Lake, McHenry, and Will counties.
During its first hundred years, Chicago was one of the fastest-growing cities in the world. When founded in 1833, fewer than 200 people had settled on what was then the American frontier. By the time of its first census, seven years later, the population had reached over 4,000. In the forty years from 1850 to 1890, the city’s population grew from slightly under 30,000 to over 1 million. At the end of the 19th century, Chicago was the fifth-largest city in the world, and the largest of the cities that did not exist at the dawn of the century. Within sixty years of the Great Chicago Fire of 1871, the population went from about 300,000 to over 3 million, and reached its highest ever recorded population of 3.6 million for the 1950 census.
From the last two decades of the 19th century, Chicago was the destination of waves of immigrants from Ireland, Southern, Central and Eastern Europe, including Italians, Jews, Poles, Greeks, Lithuanians, Bulgarians, Albanians, Romanians, Turkish, Croatians, Serbs, Bosnians, Montenegrins and Czechs. To these ethnic groups, the basis of the city’s industrial working class, were added an additional influx of African Americans from the American South—with Chicago’s black population doubling between 1910 and 1920 and doubling again between 1920 and 1930.
In the 1920s and 1930s, the great majority of African Americans moving to Chicago settled in a so‑called “Black Belt” on the city’s South Side. A large number of blacks also settled on the West Side. By 1930, two-thirds of Chicago’s black population lived in sections of the city which were 90% black in racial composition. Chicago’s South Side emerged as United States second-largest urban black concentration, following New York’s Harlem. Today, Chicago’s South Side and the adjoining south suburbs constitute the largest black majority region in the entire United States.
Chicago’s population declined in the latter half of the 20th century, from over 3.6 million in 1950 down to under 2.7 million by 2010. By the time of the official census count in 1990, it was overtaken by Los Angeles as the United States’ second largest city.
The city has seen a rise in population for the 2000 census and is expected to have an increase for the 2020 census.
Per U.S. Census estimates as of July 2016, Chicago’s largest racial or ethnic group is non-Hispanic White at 32.6% of the population, with the Hispanic population increasing to 29.7% of the population and Blacks declining to 29.3% of the population from 32.9% in 2010.
As of the 2010 census, there were 2,695,598 people with 1,045,560 households living in Chicago. More than half the population of the state of Illinois lives in the Chicago metropolitan area. Chicago is one of the United States’ most densely populated major cities, and the largest city in the Great Lakes Megalopolis. The racial composition of the city was:
Chicago has a Hispanic or Latino population of 28.9%. (Its members may belong to any race; 21.4% Mexican, 3.8% Puerto Rican, 0.7% Guatemalan, 0.6% Ecuadorian, 0.3% Cuban, 0.3% Colombian, 0.2% Honduran, 0.2% Salvadoran, 0.2% Peruvian).
Chicago has the third-largest LGBT population in the United States. In 2015, roughly 4% of the population identified as LGBT. Since the 2013 legalization of same-sex marriage in Illinois, over 10,000 same-sex couples have wed in Cook County, a majority in Chicago.
Chicago became a “de jure” sanctuary city in 2012 when Mayor Rahm Emanuel and the City Council passed the Welcoming City Ordinance.
According to the U.S. Census Bureau’s American Community Survey data estimates for 2008–2012, the median income for a household in the city was $47,408, and the median income for a family was $54,188. Male full-time workers had a median income of $47,074 versus $42,063 for females. About 18.3% of families and 22.1% of the population lived below the poverty line. In 2018, Chicago ranked 7th globally for the highest number of ultra-high-net-worth residents with roughly 3,300 residents worth more than $30 million.
According to the 2008–2012 American Community Survey, the ancestral groups having 10,000 or more persons in Chicago were:
Persons identifying themselves as “Other groups” were classified at 1.72 million, and unclassified or not reported were approximately 153,000.
71% identify as Christians (almost half of whom—35%—identify as Catholic), 7% identity with other faiths, and 22% have no religious affiliation. Chicago has many Jews, Muslims, Buddhists, Hindus, and others. Chicago is the headquarters of several religious denominations, including the Evangelical Covenant Church and the Evangelical Lutheran Church in America. It is the seat of several dioceses. The Fourth Presbyterian Church is one of the largest Presbyterian congregations in the United States based on memberships.
The first two Parliament of the World’s Religions in 1893 and 1993 were held in Chicago. Many international religious leaders have visited Chicago, including Mother Teresa, the Dalai Lama and Pope John Paul II in 1979.