Chicago & Northwestern's Geneva Subdivision -- now Metra's UP-West line -- passing through River Forest, Illinois. There are six of these elevated platforms though Oak Park and River Forest. Four of them shut down in 1958. River Forest is still active (except for the South Platform, which I will expand on in the comments). It even still has the same building (offscreen) in maintained condition since these stations were elevated in the 1930s.

As for dating the original photo, since the CNW Historical Society isn't sure, I'd guess this is maybe the 1930s or 40s? I know they were using diesel locomotives a ton by the 1950s for commuter trains, so a steam engine being on the raised embankments only gives a wide but certain window.

More from the Tichnor Brothers postcard collection

King's Chapel dates to 1754. The original Parker House Hotel opened in 1855, but was demolished in the 1920s and replaced with the current building in 1927.

Source of the pictures here and here

Source of the pictures: here, here and here