The term “nickel” wasn’t (um) coined until 1866, though the smaller half dime survived until 1873.
The modern version of the nickel, featuring Thomas Jefferson, debuted in 1938 and replaced the Buffalo nickel, according to the U.S. Mint.
As CoinWeek noted, by late 1970, the Proof Jefferson nickel master dies had worn to the point that they lacked fine detail.
One result of the recutting and redesigning process was that the 1971-S Nickel ended up with many versions, according to CoinWeek.
For example, on one of those designs, dubbed ODV-021, the T and R in “trust” on the front of the nickel are slightly thinner than normal.
Starting in 1971, San Francisco stopped producing nickels for general circulation. Since then, all nickels struck in San Francisco have been proofs, a term that refers to the coin’s finish.
The 1971 Jefferson nickel series included an error known as the 1971 “No S” Jefferson nickel because it lacks the “S” mintmark.