The third-most populous city in the United States behind New York City and Los Angeles, Chicago is an international hub for finance, commerce, technology, industry and transportation. In fact, Chicago’s O’Hare Airport is the busiest in the world. Known as both ‘The Windy City’ and ‘The Second City,’ Chicago experienced the Great Migration in the 1920s and its African-American population grew exponentially. That also had an immense cultural — and ultimately political — impact. Despite its famously brutal winters along the shores of Lake Michigan, Chicago is a major world convention destination and ranks behind only Orlando and Las Vegas in the U.S. Its nightlife and deep-dish pizza are surpassed in local’s undying love by only the Cubs and Bears. Chicago also earned a milestone moment in 2008 when Barack Obama addressed a packed Grant Park after becoming the first African-American to win a U.S. Presidential election.