In American numismatics, the most popular series to collect are the 20th century issues. Series like the Lincoln Cent, Buffalo Nickel, Mercury Dime, Walking Liberty Half Dollar and Peace Silver Dollar are all widely and avidly collected. There are three common threads that make these series perennial favorites: design, affordability and nostalgia.
Until the early 20th century, one could argue that American coin designs were meant to be more functional than beautiful. The United States Mint preferred to stick with designs for decades and decades—in many cases motifs would remain unchanged for 25 or even 50 years. Unless a design was difficult to strike or had some kind of production issue, it would remain untouched ad infinitum.
This attitude largely changed when Theodore Roosevelt took office. He felt America’s coin should be interesting and attractive. He began a trend of hiring outside artists/sculptors (not just U.S. Mint staff) to redesign America’s coinage. The result: most U.S. coin denominations were overhauled with beautiful new designs from 1907 through 1921. These early 20th century series are considered to be some of the most aesthetically pleasing in all of American numismatics.
Another major appeal of the 20th century series is that the coins are usually affordable. In the 19th century, mintages would vacillate dramatically year to year thanks to financial panics, wars, U.S. Mint surpluses and fluctuating metal prices. By the 20th century, mintages became much more consistent and robust. Another contributing factor was how rapidly the American economy and population base grew. More people meant more robust U.S. Mint output—and larger mintages.
While there are still some lower-mintage issues that command a premium, these “key dates” are more like to be $500-$5000 items, not $50k-$500k rarities. With fewer wildly expensive rarities in the way, collectors on a budget can complete a 20th century series. A complete run of 1921-1935 Peace Dollars by date, as an example, can be assembled for under $10,000 easily. An 1878-1921 complete Morgan dollar series would probably run upwards of $50k.
Lastly, collectors seem to be attracted to coins they once saw in circulation. As recently as 50 years ago, coins like Wheat Cents and Buffalo Nickels were still found in everyday pocket change. Now that they’ve vanished from circulation, these coins have become especially popular as collectibles. This is not just a recent phenomenon; when the Large Cent was discontinued in 1857, it became the first widely collected coin in American numismatics.