A: Chicago, Illinois, United States
The first test of magnetic stripe transaction card technology developed by IBM occurred in January 1970 at the American Airlines terminal at Chicago's O'Hare Airport with the Automatic Ticket Vendor.
Reference: Computer History Museum, Jerome Svigals donation, "Automatic Ticket Vendor Press Kit", October 30, 1969. X3951.2007.
Though the test at O'Hare Airport was successful, the airline did not implement the technology because of a recession. IBM patented the technology, but did not announce its availability until 1973.