Geography of Chicago
Chicago, Illinois is located in northern Illinois at the south western tip of Lake Michigan.
Chicago's present natural geography is a result of the large glaciers of the Ice Age, namely the Wisconsin Glacier that carved out the modern basin of Lake Michigan (which formed from the glacier's meltwater). The terminal moraines formed by the glacier today are low lines of hills in suburban Chicagoland. The flat plain that Chciago proper mostly lies on is the bed of glacial Lake Chicago, which was a larger precursor of Lake Michigan.
One special feature of the Chicago area was the now-vanished Mud Lake in the Des Plaines River watershed. During heavy periods of rain or when the Des Plaines overflowed its banks due to downstream ice dams in the early spring, the river would flow through Mud Lake to teh South Branch of the Chicago River, forming a favorite portage for early traders and creating the path of the future I&M and [[Chicago Sanitary and Ship Canal]s. When the city we know today was initially founded in the 1830s, the land was swampy and most of the early building began around the Chicago River mouth.
According to the United States Census Bureau, Chicago has a total area of 606.1 km² (234.0 mi²). 588.3 km² (227.1 mi²) of it is land and 17.8 km² (6.9 mi²) of it is water. The total area is 2.94% water. The city has been built on relatively flat land, the average height of land is 579 feet (176 metres) above sea level. Chicago, along with New York City and Los Angeles, California, make up the three most massive cities of the U.S., yet Chicago is only half the other two cities' individual land areas.
The Chicago Metropolitan Statistical Area (MSA) consists of Cook county and five surrounding Illinois counties as well as the Chicago–Gary–Kenosha Consolidated Statistical Area (CSA) which is made up of nine counties, two of them in northwestern Indiana and one in southeastern Wisconsin.
When it comes to skyscrapers, Chicago is king, being the first US city to reach new heights, shortly joined by New York City. Chicago, along with New York City and Hong Kong, makes up the "big three" when it comes to city skylines. Today Chicago can boast to having 5 of the 10 tallest buildings in the United States and 10 of the 50 tallest in the world.
By modern standards, Chicago has little reason to build up: being located in the Midwest, it has plenty of room to sprawl outwards on almost Euclideanesque flat ground. There is, of course, the Chicago River, which may bring some argument as to geographic restriction, but the impact of which was strongly lessened by the strict adherence to the Chicago grid across the river. Mostly though, Chicago runs on energy and inertia. Even today, Chicago is going through a massive skyscraper building boom, with projects like 55 East Erie (the tallest residential building in the US outside New York City) and Trump International Hotel (to be completed in 2007, to be the fourth tallest in Chicago and the tallest building built in the US for nearly three decades) breaking ground frequently. All this can really be attributed to precedent: Chicago has always had a history of frantic skyscraper building, mostly beginning after the Great Chicago Fire, and since this time developers simply follow the pattern set before them.
