Looking at Erie's 1900 suburban schedule for Chicago, I noticed the trains shown don't really look like conventional commuter trains. They don't run at the usual times. But the suburban schedule from 1900 linked above showed 54-trip monthly tickets were sold as far east as Crown Point. The tickets were good only by the person "named on the ticket" and for one calendar month. Who would buy those tickets if not commuters?
I looked at two other Official Guides
(1898 and 1909) that are available on-line to see if the local service offered by the Erie out of Chicago was much different than in 1900. The 1898 schedule didn't really show a conventional commuter schedule either, but the 1909 schedule showed a pair of trains -- Nos. 9 and 26 -- that would probably serve commuters pretty well.
Here's the list I made:
I notice that in the morning, at least until 1909, there is no train due in Chicago before 9:00 AM other than No. 3 which was the Vestibuled Limited
departing Jersey City in mid-afternoon. If I'm going to work I don't think I would want to count on a train coming from almost 1,000 miles away, departing it's original terminal some thirty hours earlier. In the evening, before 1909 the last train out of Chicago was at 4:10 PM. Kind of early for commuters. Yet Erie was already selling 54-trip monthlies. I wonder who would have bought them?