Chicago is the third largest city in the United States with a population of 2,886,251 (2002). The name Chicago comes from "Checagou" (Chick-Ah-Goo-Ah) or "Checaguar" which in the language of the Potawatomi Indians means 'wild onions' or 'skunk'. The area was so named because of the smell of rotting marshland onions that used to cover it.

Chicago was first settled by Europeans when Jean Baptiste Point du Sable, an African American from Haiti, settled on the Chicago River. In 1795, the area of Chicago was ceded by the Native Americans in the Treaty of Greenville to the United States for a military post. In 1803, Fort Dearborn was built and remained in use until 1837 except between 1812 and 1816 when it was destroyed in the Fort Dearborn Massacre dring the War of 1812.

On August 12, 1833, the Town of Chicago was incorporated as a town with a population of 350. Within 7 years of being incorporated, the primarily French and Native American town had a population of over 4,000. Chicago was granted a city charter by Illinois on March 4, 1837. The opening of the Illinois and Michigan Canal in 1848, allowed shipping from the Great Lakes through Chicago to the Mississippi River and so to the Gulf of Mexico. The first rail line to Chicago, the Galena & Chicago Union Railroad was completed the same year. Chicago would go on to become the transportation hub of the United States with it road, rail, water and later air connections. Chicago also became home to nationwide retailers offering catalog shopping utilizing these connections like Montgomery Ward and Sears, Roebuck and Company.

Because of the geography of Chicago early citizens faced many problems. The prairie bog nature of the area provided a fertile ground for disease carrying insects. The growth of early Chicago and its commerce was stymied by lack of transportation. In the spring Chicago was so muddy from the high water that horses would often be stuck waist deep in the street. One dirt road was so hazardous that it became known as the "Slough of Despond." Comical signs proclaiming "Fastest route to China" or "No Bottom Here" were placed out to warn passersby of the deep mud.

To address these transportation problems, the board of Cook County commissioners, at its second meeting, after being created by the Illinois legislature on January 15, 1831, decided to improve two country roads toward the west and southwest. The first road went west, crossing the "dismal Nine-mile Swamp," crossed the Des Plaines River, and went southwest to Walker's Grove, which is today known as Plainfield. There is a dispute about the route of the second road to the south.

Early Chicago was also plagued by sewer and water problems. Many people described it as the filthiest city in America. To solve this problem Chicago embarked on the creation of a massive sewer system. In the first phase sewage pipes were laid across the city above ground with gravity moving the waste. Then in 1855 the level of the city was raised 4 to 7 feet with individual buildings jacked up and fill brought in to raise streets above the swamp and the newly laid sewer pipes.

Next the city decided to work on their water problem. Because Lake Michigan was the source of water for the city and it was already highly polluted from the rapidly growing industries in and around Chicago a new way of procuring clean water was needed. The city embarked on a large tunnel excavation project and started building tunnels underneath Lake Michigan to newly built Water Cribs. The water cribs were 2 miles off the shore of Lake Michigan but they still didn't bring enough clean water because spring rains would wash the polluted water from the Chicago River into them. To solve this problem the direction of flow of the Chicago River was reversed in 1871 by the Army Corps of Engineers to prevent sewage from running into Lake Michigan.

By 1857 Chicago was the largest city in then what was known as the Northwest. In a period of 20 years Chicago grew from 4,000 people to over 90,000.

The 1860 Republican National Convention in Chicago nominated home state candidate Abraham Lincoln. In 1871, most of the city burned in the Great Chicago Fire. By this time the city had grown to a population of over 300,000. As a result of the fire much of the city needed be rebuilt, this gave city planners a clean slate to fix the problems of the past. In the following years, Chicago architecture would become influential throughout the world because of this. The first skyscraper in the world was constructed in 1885 using novel steel skeleton construction.