Answer:
Louisiana Purchase: The Land Deal of the Millennium. For a mere $15 million, Thomas Jefferson doubled the size of the United States, buying 800,000 square miles from the French that stretched from the Mississippi River to the Rocky Mountains.
The correct answer is money supply.
The money supply includes all monetary assets that are available in an economy at a specific time period. If the money supply drastically increases then inflation happens and if the money supply decreases then deflation happens. Both can cause horrors for the economy so the economists have to be careful.
It was much lighter and easier to carry unlike the coins they normally used.