Photographer:Lawrence Photo Studio, Chicago. The photographer's mark is at lower left and was hard to make out. Have included an enlargement of it that was auto corrected to best allow reading the name.
Note that it may still be copyrighted in jurisdictions that do not apply the rule of the shorter term for US works (depending on the date of the author's death), such as Canada (50 p.m.a.), Mainland China (50 p.m.a., not Hong Kong or Macao), Germany (70 p.m.a.), Mexico (100 p.m.a.), Switzerland (70 p.m.a.), and other countries with individual treaties.
Photo has been cropped, auto corrected and watermark removed. Previous upload was to establish dating, source and that there are no copyright marks on it.
{{Information |Description=Publicity photo of Perry Como met by his young fans when he arrives at a Chicago train station. |Source=[http://www.ebay.com/itm/CT-Chicago-Tribune-Photo-Perry-Como-Singer-1947-/280748973067?pt=Art_Photo_Images&hash=item415df15c