Chicago is the largest state in Illinois and is home to nearly 3 million residents, making it the third most populated city in America. Founded in 1833, Chicago is today a major hub of industry ranging from telecommunications to infrastructure. O’Hare International Airport of Chicago is considered the second busiest airport in the world in terms of traffic. Today, Chicago ranks fourth out of the world's largest metropolitan GDP. Chicago is also ranked in one of the top 10 global financial centers, and ranked by Forbes as the world’s fifth most economically powerful city. The Chicago skyline proudly displays the once worlds tallest building, the former Sears Tower, not known as the Willis Tower, as well as the Trump International Hotel also one of America's tallest buildings.