There is little information concerning when the "ice cream sandwich" was invented. The current version was invented in 1945 by Jerry Newberg when he was selling ice cream at Forbes Field. There are pictures from the Jersey Shore (circa 1905) that show Ice Cream sandwiches were popular at 1 cent each. In the picture below the horse drawn cart is selling ice cream sandwiches. Click on the link below and you can see an enlarged version.
http://www.shorpy.com/node/8578?size=_original
~ Chef ~