Though it is round, The Susan B. Anthony dollar may appear 11-sided, due to an 11-sided rim bordering the edge of both sides. The original design called for the coin itself to be an 11-sided hexadecagon, but vending machine manufacturers claimed that vending machined could only accommodate round coins. Because of their similar size and color, it was found to be very easy to mistake the coin for a quarter. The US dollar coin was released July 2, 1979. While a total of 847.5 million were minted in 1979, they failed to circulate well (despite the slogan "Carry three for Susan B.") and a minimal number were produced in 1980. In 1981 9.7 million coins were produced for numismatic sets marketed by the Mint. Many of those have been broken, and it is not unusual to find 1981-dated coins. At the end of production, the Treasury was left with hundreds of millions of the coins.

In the 1980s and into the 1990s, vending machines began to take higher denomination notes, and give change in dollar coins. This led to an increased call on the Treasury's supply. By 1998, the Treasury's stock of dollar coins was near exhaustion. The Mint lacked the legal authority to change the design of the coin, and it was not deemed possible to release the new Sacagawea dollar earlier than 2000. Accordingly, after the longest hiatus for the same design of a circulating coin in U.S. history (one year longer than for the Morgan silver dollar), the coin was restruck in 1999. The Anthony dollar is notable for numismatists because (as of 2007) it was the last coin produced for circulation by the San Francisco Mint.

Mintmarks The mintmark are is visible to the left of the collar. Mintmarks include:

* P (Philadelphia Mint in Philadelphia, Pennsylvania) 1980-
* D (Denver Mint in Denver, Colorado)
* S (San Francisco Mint in San Francisco, California)

SPECIFICATIONS: Diameter: 26.5 millimeters Weight: 8.1 grams Composition: Cupro-Nickel 12.5" Nickel, Edge: Reeded (Information gathered from - Wikipedia.org, Coin Resource.org, "The Red Book - A Guide Book of United States Coins", and other sources)