For several years, from 2001-2008 or so, I was the webmaster of theundergroundrailroad.org. I built an early site for it in Flash, and in 2007 converted it to a handmade PHP CMS with a CSS-based design that, at the time, was decently current but is now very dated.
In 2020, I realized that its longtime host had upgraded its PHP version to 7+, and the site no longer worked. At that time, I converted it to a static HTML site and put it into this repository's gh-pages branch, which automatically deploys to [https://www.theundergroundrailroad.org]. For the foreseeable future I'll continue paying the domain registration fees so the site's content, some of which is very good, can stay accessible.
The code from the 2007 redesign is in this master branch. It is kind of functional in PHP 5.6 and lower, but I certainly wouldn't recommend gleaning anything from it, or from the design style it used at that time, which is still reflected in the GitHub Pages version.