I love trains. I also love reading old maps. They're fascinating and they're a great way to learn about the city's history. I'm sharing the Chicago Aurora and Elgin Railroad which operated until 1957. If you look at the map starting in Maywood, you can see what would become the Illinois Prairie Path system of trails, which also was the first successful rails-to-trails system in the country. Often when riding on these types of trails, I feel a connection with the history of the railroad.
Aside from the IPP, you can see what the L system looked like back in the 30s. There was a Humboldt Park "L", a Douglas Park "L", what is known today as the Blue Line to O'Hare, was called the Logan Square "L". Today's Brown line was the Ravenswood "L". Wrigley Field was called Cubs Ball Park, and US Cellular/Comiskey, was White Sox Ball Park.
You can geek out for a few minutes here and learn a lot about the city and burbs, enjoy.
Like many of you here, I'm a transit and map nerd. I was really excited to dig into the 1890 bike map someone posted earlier, but I couldn't get the link to open. However, I found the full page of maps, including that one, here:
I just wanted to share in case any others had a similar problem with the earlier link.