From the Indiana University Archives:
Charles Weever Cushman, amateur photographer and Indiana University alumnus, bequeathed approximately 14,500 Kodachrome color slides to his alma mater. The photographs in this collection bridge a thirty-two year span from 1938 to 1969, during which time he extensively documented the United States as well as other countries.The above photograph is dated September 4, 1950. The description reads "Ice cream vendor supplies 2nd story at Halsted & Cabrini Chicago." (More info on this photograph here.)
I'm about to make a lame joke about the vendor being a second-story man. So before I do, start browsing:
Charles W. Cushman Photograph Collection (Indiana University Archives / Digital Library Program)
(Thanks to Michael at Brown Studies for pointing me to this collection.)