Chicago was incorporated as a city in 1837, near a portage between the Great Lakes and the Mississippi River watershed. (A portage is a water gap connecting the watersheds and the navigable waterways of the Mississippi River and the Great Lakes).

Chicago is the 3rd most populous U.S. city (behind both N.Y. City and L.A.) with over 2.7 million residents. Among cities, Chicago has the 4th largest gross domestic product behind N.Y. City, L.A., and Tokyo. It ranks ahead of both London and Paris.

Chicago occupies 234 square miles. Land makes up 227 square miles with the rest consisting of water. Chicago has an elevation of 597 feet.

Abraham Lincoln was nominated for the U.S. presidency at the 1860 Republican National Convention in Chicago.

Chicago has 2 professional baseball teams (Cubs and White Sox), an NFL team (Bears), NBA club (Bulls), and the Blackhawks of the NHL.

In 1871, the Great Chicago Fire broke out. It destroyed an area approximately 4 miles long and 1 mile wide, a large section of the city at the time. Much of the city (including railroads and stockyards) survived intact. From the ruins of the previous wooden structures arose more modern buildings of steel and stone which would set the precedent for worldwide construction. During its rebuilding period, Chicago constructed the world's first skyscraper in 1885 (Home Insurance Company) using steel-skeleton construction.

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