So a while ago I decided to move away from my usual beat of mapping historical elections and move over to mapping historical transit networks, with a focus on the US because so many of their cities tore up their networks completely in the 1950s and 60s. As a starting point for this, I thought I'd do the granddaddy of them all: Chicago, which in addition to its famous 'L' trains boasted the largest streetcar network in the world by track mileage - the figure I've seen is 1,600 miles of track, which I'm pretty sure counts double-tracked lines twice - even so, it'd be five times the size of current world leader Melbourne. The map I've begun to make shows the network on October 1st, 1947, the day the 'L' and the streetcar system were brought under a common, publicly-owned operator in the form of the Chicago Transit Authority (CTA), which is still with us today and still operates the 'L' and buses.
I'm drawing off two main sources for Chicago: firstly, Gábor Sándi's GS Tram Site, whose Chicago map provided the first impetus to work on this and remains a good overview source for what lines ran where, and secondly, the Illinois Railway Museum's online CTA history collection, which provided both more official maps that indicated several errors with the former source, and route books that list the exact alignments of all the lines and save me a lot of second-guessing where the maps are unclear. The only thing I'm doing off-hand are the stops, which I'm basing on the locations of modern-day bus stops and a degree of conjecture for those streets that no longer even have bus service.
The current WIP, attached below, should be complete for the Loop (the city centre, so named for the 'L' tracks that run in a loop around it) as well as the North Side, i.e. everything north and east of the Chicago River, with most of the lines in place for the Northwest Side, i.e. points west of the river and north of Division Street. It's already quite big, as you can plainly tell, and I imagine this is about a fifth of the size it's going to end up being.
chicago-tram-1947.png
EDIT: And just to state the obvious, the key isn't nearly complete either even if it looks finished.