What years did US nickels contain silver?

From mid 1942 through 1945 US nickels contained 35% silver, 56% copper, and 9% manganese. Nickel was eliminated because it was needed for the war effort.

"War nickels" are identifiable by their grayish color and the presence of a large mint mark over the dome of Monticello.

Regardless of any other urban legends, internet rumors, or tall tales, NO other US nickels ever contained silver. Except for war nickels, the coin has been made of a 75% copper / 25% nickel alloy since its introduction in 1866.

Trivia fact: War nickels were the first US Coins to carry a P mint mark for Philadelphia, and the only such coins until it was reintroduced on 1979 dollars.