During its first hundred years , Chicago was one of the fastest-growing cities in the world . When founded in 1833 , fewer than 200 people had settled on what was then the American frontier . By the time of its first census , seven years later , the population had reached over 4,000 . In the forty years from 1850 to 1890 , the city 's population grew from slightly under 30,000 to over 1 million . At the end of the 19th century , Chicago was the fifth-largest city in the world , and the largest of the cities that did not exist at the dawn of the century . Within sixty years of the Great Chicago Fire of 1871 , the population went from about 300,000 to over 3 million , and reached its highest ever recorded population of 3.6 million for the 1950 census
Great Chicago Fire of 1871
Great Chicago Fire
Chicago