This book includes maps from the 1670s to the present as well as essays about different aspects of Illinois history. The maps record boundary changes, detail the growth of towns (both large and small), and chart railroad and industrial expansion in the state.
Maps make great resources for family historians too. Trace your ancestors with Family Maps of Cook County, Illinois compiled by Gregory A. Boyd.
If you family was an early settler in the area, they may have received a land patent. Boyd gives you three maps: a land patent map, a current (ca 2006) road map, and a historical map which lists cemeteries, railroads, and waterways. Look for you family in the surname index or search the map of your ancestors town and neighborhood to find family names.
While land patent maps sound confusing, they're easy to use. For example, here you see a road map of Glenview. The library would be located in box 35.
And here is the land patent map. You can see that Edwin Clark received a patent for the land the library currently sits on in 1840.
And for more historical maps, check out the map case in the Genealogy & Local History Room.