Carnegie Library of Pittsburgh digitizes material from its collections in order to create greater access to them. This page will help you locate those digital collections and learn how to access them.
One of my favorite non-CLP resources for doing historical research about the city is Historic Pittsburgh. Hosted by the University of Pittsburgh, this website hosts digitized content from more than a dozen libraries and archives around the city, so it’s a great one-stop-shopping experience for genealogy, house histories, archival research, and – my personal, preferred time-suck – historic photos!