Wars often redirected metal resources. For example, during World War II, the U.S. switched from copper to zinc-coated steel for pennies in 1943 to save copper for ammunition.
Mint closures or interruptions during conflict resulted in limited coin production. The Civil War saw many Southern mints cease operations, producing only a few rare coins.
Silver shortages deeply affected coinage. In the 1960s, rising silver prices led to the removal of silver from U.S. dimes and quarters starting in 1965.
Hoards and panic buying during wartime led people to stash coins, removing them from circulation. This makes surviving examples in good condition even scarcer.
Inflation and devaluation altered coin designs and metal content. Hyperinflation in some countries led to high-denomination coins that were quickly withdrawn.
Coins struck during transitions—like the shift from silver to clad—sometimes resulted in rare transitional errors.
Commemorative coins were often issued during or after wars, like the 1925 Lexington-Concord Half Dollar, adding historical and patriotic value.