The story behind large-denomination currency
This is still legal tender:
You wouldn’t want to drop it.
In 1928, the federal government overhauled its system of printing banknotes. It shaved about an inch of length and just under a half of an inch in width off of the bills and issued the new smaller bills in the $1 to $100 denominations with which we’re familiar. However, the Treasury also issued larger denominations. They featured William McKinley ($500), Grover Cleveland ($1,000), James Madison ($5,000), and Salmon P. Chase ($10,000). …
When the Treasury discontinued the bills, they rapidly fell out of circulation. However, a few are still lingering; as of May 2009, there were still 336 $10,000 bills at large. At the same time, Slate reported that there were also 342 $5,000 bills and 165,732 $1,000 bills still floating around.
The large bills are now worth more than their face value, of course.
There was also a $100,000 bill that was printed, but it wasn’t put into general circulation.
11:14pm 
