Often called The Windy City or The City of Broad Shoulders, Chicago was incorporated as a city in 1837 after initailly being founded in 1833 at the site of a portage between the Great Lakes and the Mississippi River watershed. The city soon became a major transportation hub in North America and quickly became the transportation, financial and industrial center of the Midwest. Today the city's attractions bring 44.2 million visitors annually.

Chicago was once the capital of the railroad industry and until the 1960s the world's largest meatpacking facilities were at the Union Stock Yards; currently the city is home to the nation's second busiest airport, O'Hare International. Chicago became notorious worldwide for its violent gangsters in the 1920s, most notably Al Capone, and for the political corruption in one of the longest lasting political machines in the nation. The city has long been a stronghold of the Democratic Party and has been home to many Democratic presidential candidates including the current presidential nominee, Barack Obama.

source from : www.wikipedia.org