I now have code that can pull out lists of tracts ordered by city and year, in the form of <span>s with meaningful ids, as well as a list of cities in the form of a select object. I'm getting to the point where I can start to write the actual GUI code.

I've decided to forgo the use of JQuery and other such bloat, in favour of re-using the AJAX code I wrote for ColDesp and Mariage. That'll be a lot cleaner and easier to debug.