Chicago on Lake Michigan in Illinois, is among the largest cities in the U.S. Famed for its bold architecture, it has a skyline bristling with skyscrapers such as the iconic John Hancock Center, sleek, 1,451-ft. Willis Tower and neo-Gothic Tribune Tower. The city is also renowned for its museums, including the Art Institute and its expansive collections, including noted Impressionist works. Chicago is called the "Windy City", "Chi-Town", "Second City," and the "City of Broad Shoulders". Chicago incorporated as a city in 1837 after being founded in 1833 near a portage between the Great Lakes and the Mississippi River watershed. The city soon became a major transportation hub in North America and the transportation, financial and industrial center of the Midwest. Today the city's attractions bring 44.2 million visitors annually. O'Hare International is the second busiest airport in the world. The city has a notable and famous political culture, is a stronghold of the Democratic Party, and has been home to numerous influential politicians, including the first African-American President of the United States, Barack Obama.