Why are there so many 1964 nickels?

Answer 1

As you remember, 1964 was the year of the Great Coin Shortage. For decades the price of silver had been fixed by law at $1.29/oz, so that silver coins all had constant metal values. But when the supply of silver began to dry up, Congress deregulated the price in hopes of making mining more profitable. But instead speculators, most notably the Hunt brothers in Texas, drove the price to outrageous levels - at one point, around $50/oz. That made silver coins worth far more than their face value and people began hoarding and selling to metal dealers.

The Mint was forced to look for new metals for coins, but their research took the better part of a year because they had to find something that would be compatible with existing coin presses and would work in vending machines. In the meantime, dimes, quarters, and halves were disappearing from circulation. Stores had trouble making change; some gave a discount if you paid with coins instead of bills. To take some of the pressure off the economy while researching new metals, the Mint churned out billions of nickels as a stopgap measure. It might require 10 nickels instead of a half-dollar* but at least it was still possible to make change.

There were SO many 1964 nickels made that it's still one of the more common dates in circulation. Unless you find one in absolutely perfect condition it's only worth 5 cents.

Silver coins disappeared from circulation much faster than anyone expected, and it took until around 1968 to mint enough cupronickel "sandwich coins" and return things to normal.

(*) Unfortunately, the Mint decided to keep striking half dollars in silver, albeit at a reduced percentage. But at $50/oz there was still enough silver to make them worth melting. By the time they too were changed to "Sandwiches", the coin had effectively stopped circulating.