Wow,do I ever remember the old Dunning branch. I also live very near the corner of Oak Park and Addison, and live in the house my parents bought in 1953. While I moved all over the country, I wound up back in the house I grew up in. There certainly was a branch line coming off of the old Milwaukee Road mainline near Grand Avenue that used to come up to Dunning at around Nashville Avenue. When I was a child, I used to go over and visit a friend that lived on the 3500 block of North Natoma Avenue, as their back yard extended all the way down to the railroad tracks, where the townhouses now stand. If I remember correctly, there was one train that came up on Thursday afternoons to Dunning. This was probably in the late 1950's or early 1960's. The right of way split what is now Zion Memorial Park (the old Rosemont and Mount Mayriv Cemeteries) and we used to walk up the right of way up to Byron Avenue, where the city had a huge pile of sand, about two stories tall, that we used to play on. Mount Mayriv Cemetery used to be surrounded by a high concrete wall, and a passerby was unable to see into the cemetery, but there was a small pedestrian gate that was bolted shut that opened onto the railroad right of way just north of Addison Street. We kids tried to cut the bolt on the gate so we could get in and explore, but were not successful. Mount Olive Cemetery was also split in two, and there were a pair of gates on either side of the railroad siding. Right where the parking lot for the townhouses, and the condo building sit on Addison street, there used to be a white brick gasoline station. Behind the station, there was a small wooden building, not much larger than an outhouse, that had two low stories, along with a hand operated switch to a small siding that ran behind the gas station. Never knew quite what that was there for. In those days Dunning was an active mental institution and the train would block traffic on Irving Park Road while the staff opened the gates to the center.
In addition to this train, my father told me about a streetcar that was used to transport patients from Cook County Hospital out to Dunning on a weekly basis. I subsequently saw pictures of this streetcar in a book entitled "Chicago Surface Lines" which is a history of streetcar service in Chicago.
Going back to the siding, I remember as children that we would be walking along there with our dog, and we would hear the siren at Dunning going off, signaling that an inmate was missing or escaped. We had strict instructions to stop everything and run back home when hearing that siren.
On a similar note, I imagine that a lot of people don't realize that Oak Park Avenue used to pretty much end at Irving Park Road, and start up again at Forest Preserve Drive. There was a dedicated street through there, but the street was never paved and almost impassable. I believe it was also in the early 1960's when that was opened up. Sorry I don't have any pics of the siding, but I remember well walking along it, and waving to the engineers when they went by with their trains.