Behind the $$$

The base currency of the United States is the U.S. dollar. It is printed in bills in seven denominations: $1, $2, $5, $10, $20, $50, and $100. Previously there have also been five larger denominations: $500, $1,000, $5,000, and $10,000 were printed for general use (in large transactions), and a $100,000 bill for certain internal transactions.

Although they are still technically legal tender in the United States, high-denomination bills were last printed on December 27, 1945, and officially discontinued on July 14, 1969, by the Federal Reserve System, supposedly due to 'lack of use'. The $5,000 and $10,000 effectively disappeared well before then.
The Federal Reserve began taking high-denomination bills out of circulation (destroying bills received by banks) in 1969, after an executive order by President Nixon. As of May 30, 2009, only 336 $10,000 bills were known to exist; 342 remaining $5,000 bills; and 165,372 remaining $1,000 bills Due to their rarity, collectors often pay considerably more than the face value of the bills to acquire them. Some are even in museums in other parts of the world.

For the most part, these bills were used by banks and the Federal government for large financial transactions. This was especially true for gold certificates from 1865 to 1934. However, the introduction of an electronic money system has made large-scale cash transactions obsolete. When combined with concerns about counterfeiting and the use of cash in unlawful activities such as the illegal drug trade and money laundering, it is unlikely that the U.S. government will re-issue large denomination currency in the near future, despite the amount of inflation that has occurred since 1969 (a $500 bill is now worth less, in real terms, than a $100 bill was worth in 1969). According to the U.S. Department of Treasury website, "The present denominations of our currency in production are $1, $2, $5, $10, $20, $50 and $100. The purpose of the United States currency system is to serve the needs of the public and these denominations meet that goal. Neither the department of the treasury nor the Federal Reserve System has any plans to change the denominations in use today."