Did you ever want to know in which congressional district your town, city, or county was located in say 1789, 1860s, 1920s, etc.? Got the idea from answering a question in another thread for the 1789 lines and found the data. You can view the old lines in Google Earth.
Step 1: Dl the zip at
http://cdmaps.polisci.ucla.edu/Step 2: Convert the zip at
https://www.gisconvert.com/ Select output as KML
Step 3: Post dl, double click or File Open the KML file in Google Earth to have the old lines overlaid on top of the current map of the United States.
This was probably done on here before but just discovering the data files and the way to do this and thought it was cool.