DuPage County, Illinois was established as an Illinois political subdivision in 1838. Located in northeastern Illinois, it is bounded on the east and north by Cook County, on the south by Cook and Will Counties and on the west by Kane County. The City of Chicago is located ten miles east of DuPage’s eastern boundary.
The County is square in shape except for a “tail” which extends south from the southern border of the County’s southeast corner. There are nine townships. Eight of the nine are squares, six miles to a side, while the ninth, Downers Grove Township, the one with the tail, is roughly half again as large as the others. Overall, the area within the DuPage County boundaries is about 334 square miles.
In 1860, DuPage County’s population was 14,697; there were 1,251 farms and more than two-thirds of those employed were engaged in farming or farm-related occupations. In 1900 the population was 28,196, by 1940 it had risen to 103,480 and in 2000 the population was close to 1,000,000 and there were fewer than 100 farms.