By size (though not value), the dime is the smallest coin used regularly in the United States, with a diameter of just under 18 millimeters. In the past, particularly during the 19th century, this wasn’t always the case. The half dime (same face value as today’s nickel, but made out of silver) was just 15.5 millimeters across when the denomination ended in 1873.
From 1851 to 1873, the three cent silver coin was even smaller, only 14 millimeters in diameter. Its weight was just four-fifths of a gram—less than the average paper clip. They were nicknamed “fish scales” for their thinness and size. Even the three cent silver pieces don’t take the tiniest-coin honor for regular U.S. coinage.
Instead, the short-lived first version of the gold dollar takes that honor. This 1849-D gold dollar illustrates the Type One or initial design. Like other Type One gold dollars, it is just 13 millimeters across. (All coins in this post are part of Heritage’s March 2010 National Money Show auction in Fort Worth.)
As so many numismatists like to say, the Type One gold dollars “proved unsatisfactory.” (Read: too darn small!) Mint employees turned out a series of experiments and patterns, some retreads of old ideas, in their quest to improve the design. One of the more intriguing patterns to come out of this quest is an annular design that tried to broaden the diameter of the gold dollar without decreasing the thickness.
The trick involved putting a hole in the middle of the coin, a style not seen on any official United States coinage, though it is used elsewhere in the world, notably on current five yen coins of Japan.
Eventually, the Mint settled on a broader and thinner planchet, diameter 15 millimeters, as its solution. The first design for the new dimensions, the so-called Type Two, was a bit of a bodge, but it was corrected swiftly, and the final Type Three design stayed more or less stable until the last circulating gold dollars were struck in 1889.
The gold dollar wasn’t the only denomination to grow in size, either. The tiny three cent silver coins were struck through 1873, but it was in 1865 that they really met their match, when the Mint first issued a three cent coin in copper-nickel. The three cent nickel has a diameter identical to that of today’s dime.
The half dime also got a larger copper-nickel replacement in the same year. While the design of this 1866 Shield nickel may not look familiar, the size should; at 20.5 millimeters, it’s just a touch smaller than the modern five cent coin. The nickels jingling in our pockets are throwbacks to the days when a lot of little coins got just a little bit bigger.