What were US nickels made of before 1965?

Please don't assume that because a US coin was minted before 1965 it has to contain silver. That was the case only for higher-denomination coins like dimes and quarters. All US nickels except those minted during WWII have been made of an alloy of 25% nickel and 75% copper.

The only exception to this happened during WWII when nickel metal was needed for the war effort. From October 1942 to December 1945 special "war nickels" were minted. These coins are 56% copper, 35% silver and 9% manganese, and can be identified by a somewhat darker color and a large mintmark letter over the dome of Monticello. internet rumors to the contrary, these are the only US nickels that ever contained any silver.