there was once a $1 coin with Sacagawea on it...and also Susan B, Anthony..each one a different size...so slot machines and other coin operated machines (esp. in post office) need to be adjusted to take different sizes of coins...i wonder how this works..

The susan b anthony was a small coin...with 11 sided edges that looked squared off ..it was too close to the size of a quarter, and was often
confused with them.

http://en.wikipedia.org/wiki/Sacagawea_dollar

http://en.wikipedia.org/wiki/Susan_B._Anthony_dollar