My first reaction to your comment, Sara, was to say that our current (i.e. prior to the relatively recent change in the appearance of the $20, $50, and $100 bills) currency looks exactly like the currency in use in the 60s when I was a kid. But rather than depend on my memory, I did a quick net search and learned the following:
The basic face and back designs of all denominations of our paper currency in circulation today were selected in 1928, although they were modified to improve security against counterfeiting starting in 1996. A committee appointed to study such matters made those choices. The only exception is the reverse design of the one-dollar bill. Unfortunately, however, our records do not suggest why certain Presidents and statesmen were chosen for specific denominations.
Anyway, all the sites I visited agreed that the currency was basically the same prior to the anti-counterfeiting measures in 1996, which was after the Tempus Fugitive episode. The only difference is the series number and the signature of the current Secretary of the Treasury. But since currency from different periods is always in circulation and is recognized and guaranteed by the US gov't, no one would notice that their money had the "wrong" signature on it.
I was, however, amused by your comments about credit cards, which reminded me how ubiquitous they had become in modern life. Back in the 60s, there would have been no credit card to use because credit cards only existed for specific businesses (i.e. a Conoco gas card or a Sears card). MasterCard and Visa (and the host of their imitators) hadn't come into existence yet, so L&C would very definitely have paid cash for their rental car.
Thanks for the trip down memory lane
