While I can't make out the entire cancel, there is enough here to determine the company that placed the cancel on the stamp. Especially with the reference in the cancel to "The Belt" railway. The Chicago and Western Indiana Railroad owned the Dearborn Station in Chicago including all the tracks leading into it. The C&WI was owned by five railroads that used the station, so that those railroad did not need their own lines leading into arguably the most important railroad city in the world at the time. The C&WI is now a part of the Union Pacific Corporation.
C&WI Timetable from 1963