How long have nickels been made?

Answer 1

The first US nickels were minted in 1866.

Before that, the only 5-cent piece was a tiny silver coin called a "half dime". It was unpopular because it was so small that it was easy to lose. Half dimes continued to be minted until 1873. By that point there were enough nickels in circulation, and the US Mint stopped making half dimes.

The first Canadian nickels were minted in 1922.

Before that Canada also had a tiny silver coin very much like the US half dime, although its name was simply a five-cent piece. Like its US counterpart it was unpopular because of its small size; it was colloquially called a "fish scale".