
Based on established numismatic information, United States nickels were produced with a silver composition for a specific period during World War II. The years for these silver-alloy nickels are from 1942 to 1945.
The change in metallic composition was a direct result of the war effort. Nickel was a critical and strategic material required for armor plating and other military applications. To conserve this metal, the United States Congress authorized a change in the five-cent piece's alloy. The new composition consisted of 56% copper, 35% silver, and 9% manganese. This was a significant departure from the standard 75% copper and 25% nickel alloy used for the coin before and after this period.
These particular coins, often referred to as "war nickels," are easily identifiable by the large mint mark (P, D, or S) placed prominently on the reverse side, directly above the dome of Monticello. This was the first time the Philadelphia mint used a "P" mint mark on a coin. After the war concluded, the U.S. Mint reverted to the original copper-nickel composition in 1946, ending the production of silver-content nickels. It should be noted that the provided search result text was insufficient for formulating this answer.


