The metallic composition of United States 50-cent pieces, commonly known as half-dollars, is entirely dependent on the specific year they were minted. The silver content has changed significantly over time due to shifts in legislation and the economic value of precious metals.
For a long period ending in 1964, all circulating half-dollars were composed of 90% silver and 10% copper. This standard composition applies to well-known series such as the Walking Liberty, the Franklin Half-Dollar, and the first year of issue for the Kennedy Half-Dollar in 1964. These coins are widely sought after for their high precious metal content.
A significant change occurred with the passage of the Coinage Act of 1965. From 1965 through 1970, the composition of the Kennedy Half-Dollar was altered to a "silver-clad" structure. These coins contain a reduced overall silver content of 40%. Their construction consists of outer layers with an 80% silver and 20% copper alloy bonded to an inner core of 20.9% silver and 79.1% copper.
Beginning in 1971, silver was completely removed from all 50-cent pieces intended for general circulation. Half-dollars minted from 1971 to the present day are made from a copper-nickel clad composition, featuring outer layers of 75% copper and 25% nickel bonded to a pure copper core. An exception exists for special commemorative issues and collector-grade proof sets produced by the U.S. Mint after 1971, which have been struck in various silver compositions, including 40%, 90%, and even 99.9% silver for modern releases.
