The U.S. has been making money since 1792. That first money was in the form of coins.
These early coins were made of precious metals and had actual value. It wasn't until 1862 during the Civil War that the Department of Treasury produced paper money, which isn't actually paper; it's cotton.
It was created to make up for the coin shortage. Since those early coins contained valuable metals, Americans began hording them as a hedge against the fluctuations in money created by the war.