Features
Each quarter featured an iconic image on the "tail" side of the coin. Many states allowed citizens to design images for the coins.
Time Frame
Five new quarters were released each year. In 2009, quarters from the District of Columbia, Puerto Rico, Guam and American Samoa will be released as part of the District of Columbia and U.S. Territories Program. During the program's entirety, more than 34 billion quarters have been produced for circulation.
Fun Fact
The U.S. Mint estimated that 147 million Americans have collected coins during the program (see Reference 2)--an average of one person per household in the United States.
Benefits
The U.S. Treasury estimated the program netted $6.1 billion in seniorage, or the profit gained when issuing currency. Because the quarters cost less than five cents to make, the government profited when a collector chose not to spend the coin.
Potential
The program's popularity spawned other special coin designs, including the soon-to-be-released America the Beautiful Quarters, which promote National Parks.