When was the first US nickel made?

Answer 1

The first true US 5 cent nickel containing 75% copper and 25% nickel was minted in 1866 and was called the "Shield" nickel.

Before that, the US minted tiny, 90%-silver "half dimes" to handle the 5 cent denomination. Half dimes continued to be minted until 1873, by which time there were enough nickels in circulation.

Regardless of popular myths and rumors, half-dimes were the ONLY 5-cent coins to be made of 90% silver. All modern nickels except the famous "war nickels" from WWII are made of the copper-nickel alloy noted above. War nickels were minted from mid-1942 to 1945; they were made of 35% silver, 56% copper, and 9% manganese because nickel metal was needed for the war effort.