To eliminate wasteful spending from the Federal Reserve to create 1 cent/pennies. The most highly thrown away currency. It costs the US 1.7 pennies to create 1 penny itself.
Once the manufacturer of pennies has stop we would have a trade in program with the banks to eliminate the pennies from the market. Once the trade in program is in place we would also have the banks recycle the pennies for other needs which fit when the time comes