Cartographer Dennis McClendon's "labor of love" is a website called Chicago in Maps that makes it easy to find a variety of maps of that city.
For example, there are direct links to over three dozen historic maps of Chicago, from 1834 to 1921. The thematic maps include Chicago railroad maps, transit maps and geological maps. The current maps include downtown Chicago in 2010 and a 2014 Chicago street guide. A click on the Sources and Links page provides links to guides to house numbers and street name changes, original surveyors maps and notes for Cook County and more! You can visit this helpful free website here.