The story of American 90 percent silver coinage, why it vanished from circulation in 1965, and why collectors still seek it today.
Nine parts silver, one part copper. For more than 170 years that recipe WAS American money, a standard so durable that three lifetimes of citizens never handled anything else. This is the biography of the alloy itself.
The Coinage Act of 1792 established federal silver coinage at a fineness a whisker under ninety percent, and in 1837 the standard was tidied to a clean .900 fine, where it stayed for the next 127 years. The ten percent copper was pure engineering: soft precious metal alone cannot survive commerce, and the alloy let a dime endure decades of pockets with its design intact, the same logic behind crown gold.
Keeping coin value aligned with metal value required perpetual maintenance. By 1853, rising silver prices forced the Mint to trim the metal in small denominations, marking the change with arrows beside the date, an early confession that the marriage of face and metal value needed counseling. The Act of 1873 reorganized the system again and, by ending free silver coinage, lit a political fire that burned for decades and eventually delivered the Morgan dollar.
The standard died of success: postwar silver demand pushed the metal’s value above the faces of the coins carrying it, and the Coinage Act of 1965 replaced 90 percent dimes and quarters with clad copper-nickel. Coins dated 1964 became the standard’s tombstone year, and the public promptly proved Gresham’s law by pulling silver from circulation within a few short years.
Billions of those .900 coins survive, and they built two collecting worlds at once: bulk junk silver valued by simple metal math, and the great numismatic series, Morgans, Peace dollars, Mercuries, Franklins, collected date by date. One alloy, two hobbies, and the full field guide to finding it lives in Which US Coins Contain Silver.