A: Manhattan, New York, New York, United States
In February 1950 the Diners Club issued the first "general purpose" credit card, invented by Diners Club founder Frank X. McNamara. The card allowed members to charge the cost of restaurant bills only.
"The first credit card charge was made on February 8, 1950, by Frank McNamara, Ralph Schneider and Matty Simmons at Major's Cabin Grill, a restaurant adjacent to their offices in the Empire State Building" (Wikipedia article on Diners Club International, accessed 02-28-2012).