I bought a sandwich from a vending machine today, put a $5 bill into the slot and got back $1.25 in coin for change. Not 5 quarters, but a dollar coin and a quarter. From 1794 until 1978 the one dollar coin was large and heavy and until 1964 were made primarily of silver, hence the "silver dollar". Beginning in 1979 a new smaller dollar coin was introduced. It is estimated that if the new smaller dollar coin were to replace the dollar bill the savings over 30 years would be about $5.5 Billion dollars.
Unfortunately the smaller coin has been very unpopular and is rarely seen in common circulation. About the only place it is used is in vending machines. There are several series of the new coin. This is the reverse (tails) of the Presidential series. The obverse (heads) is the portrait of one of the presidents this being a 2011 coin with Ulysses S. Grant. The history of the American dollar is quite interesting and this is already too wordy. If you want to read all about it see
Wikipedia.
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