Live site: https://www.oldnyc.org
The static content for this site lives in oldnyc/oldnyc.github.io. In particular you may be interested in the giant JSON data file which contains all the data served on the site.
This repo contains Python code used to generate the data for the site.
To get going on development:
git clone git://github.com/danvk/oldnyc.git
cd oldnyc
poetry install
See howto.md for more details on how to perform specific tasks.
If you're interested in building your own "Old" site using this code, check out this great writeup on Old Ravenna.