The blog Mental Floss has a post, A $100,000 Bill? The Story Behind Large-Denomination Currency, that discusses large denomination American legal tender. Before wire transfers, banks used them to exchange large amounts of money.
The faces on the bills were William McKinley ($500), Grover Cleveland ($1,000), James Madison ($5,000), Salmon P. Chase ($10,000) and Woodrow Wilson on the largest, $100,000.
Interestingly enough, Salmon P. Chase was also the face pictured on the first dollar bill. Why you ask? He was the Secretary of the Treasury who was charged with designing the first greenback and, in a fit of humility that reminds one of our current day politicians, he put his own face on the bill.
Well, who knows, a trillion dollar debt here, a trillion dollar debt there, and maybe inflation will kick in and fill all our wallets with enough Wilsons to be barely able to afford a carton if eggs.
As a parting thought, I was reminded of the Simpson's episode where Monty Burns had stolen the trillion dollar bill meant to pay for the Marshall Plan. Fleeing from the law he ended up in Cuba with Homer. Alas, like you know who, he was rather too trusting of dictators:
Mr. Burns: All we ask is preferential treatment because of my fabulous wealth![Burns holds the trillion dollar bill up.]
Castro: May I see?
Mr. Burns: Ho ho ho, see with your eyes, not with your hands!
Castro: Please, we are all amigos here!
Homer: Mr. Burns... I think we can trust the president of Cuba.
Mr. Burns: [hands it to Castro, and waits a couple of seconds.] Now, give it
Castro: Give what back?
Mr. Burns: D'oh...