The City of Chicago was incorporated as a city in 1837, near a portage between the Great Lakes and the Mississippi River watershed. With a population of 2.7 million people, it is the third largest city in the United States after New York and Los Angeles.

Chicago is an international center for finance, commerce, industry, technology, telecommunications, and transportation. In fact, its O'Hare International Airport is the second busiest airport in the world. The city metropolis area has a GDP of 570 billion dollars, making it the third largest in US after NY and LA. Hopefully, you already know all these facts about Chicago. Here is a list of what you don't know about the city.

1. Chicago Post Office located at 433 W. Van Buren is one of the few post office facilities in the world that you can drive a car through. Chicago was at the height of Postal communication innovation before it was overtaken by e-mail as an easier way of communication.

2. "These Are My Children", the first ever TV Drama series was first aired in Chicago’s NBC station in 1949 thus making Chicago the birthplace TV Soaps operas and sitcoms.

3. In 1952 at Chicago’s International Amphitheater became the first host of the Democratic National Convention that was televised from coast to coast.

4. Lincoln Park Zoo in the heart of Chicago is free. You can enter the facility, take pictures and see all the animals free of charge.

5. The first steel railroad was produced in Chicago in 1865. To keep its record as a city of firsts, it also became home to the first blood bank in 1937

This list is inexhaustible. Chicago is certainly a global leader in hundreds of inventions as well as sports. It is also home to world beating personalities, President Barack Obama being one of these. If you ever want to see Chicago, there is no limit to the number of firsts you will realize the city led the world in achieving.