Chicago is the largest city in the Midwest and the third-most populous city in the United States, with over 2.8 million people. Chicago is informally called the Second City, the Windy City, and the City of Big Shoulders — the last from Carl Sandburg's poem “Chicago.” Chicago was founded 1833 as a town to link the Great Lakes with the Mississippi River system.

It soon became a transportation hub of the Northwest Territory, with major connections by steamboats, canals and (by 1855), railroads. By 1890, it was one of the ten most influential world cities, the same time its population reached 1 million people. After the Great Chicago Fire of 1871, the city experienced rapid rebuilding and growth and the first skyscraper was constructed in 1885 using steel-skeleton construction.

In 1893, Chicago hosted the World's Columbian Exposition on former marshland at the present location of Jackson Park. The Exposition drew 27.5 million visitors, and is considered among the most influential world's fairs in history. Since the early 1990s, Chicago has seen considerable investment in infrastructure, revitalizing downtown theatres, neighborhoods and retail districts, and improving lakefront and riverfront cityscapes.