You may need information from sources beyond the "traditional" library resources such as scholarly articles and books. Librarians are happy to help you brainstorm what type of information you need, who might collect or disseminate it, and how you might access it.
"Milwaukee Elevated Tracks (just before completion)" by Chicago Transit Authority is licensed under CC BY-NC-ND 2.0
Ask yourself these questions to figure out where to look for the information you need:
Tip: Visit the Data Portals & Geospatial Data tab on this guide to browse some of the information that's available.