Dig DC is the online home for the DC Public Library's Special Collections. If you visit it, you can find historical DC cartoons, photographs, maps, oral histories, postcards, and other ephemera, as well as extensive metadata about each item. Cool, right? The site uses a platform called CONTENTdm, which is used by many, many libraries across the country. ContentDM's API documentation is minimal. This page covers what you need to know to see what collections are on Dig DC, view what they contain, and download collection files.
The dump.py script provides an example use case. It creates a JSON array of collections and adds in the full metadata for all records in each collection.
These scripts and documentation were created for DC Public Library by Code For DC volunteer Emanuel Feld.