I always found it a bit odd that "Peoria" is spread all over the area around Peoria, IL whereas Springfield is on the map exactly once. Then after I became an activist I started noticing that this isn't the only map you can find with a Springfield on it. The other Peoria's I know about don't sprinkle the word liberally across an area the way this one does though.

I think the word "Peoria" means "a place to go and trade" in the local indegenous language. This makes sense since Peoria Lake has been about as high on the Illinois River as you could take a big barge since way back when. In the olden days people would take skins and corn and so forth to Peoria, and cart home whatever they got for it. Nowadays there is a coal burning power plant by the river there, and CILCO provides power to the surrounding area (quite a few countys) from it. Tug boats chug another huge barge of coal there frequently. There used to be factorys there to, but a lot of them closed when the work got offshored.