In frontier areas, before and after the US Revolution, money was in short supply, precious metal coins could be the preferred method of exchange.
One of the most valuable tradable commodities on the frontier were deerskins, or ‘buckskins’, used to make tents, coats, moccasins, hats, etc. Native Americans traded these buckskins with European colonial settlers and immigrants for goods or services; the skins acted as currency units.
Early references to the term ‘buck’ include a cask of whisky exchanged for five buckskins. Other theories refer to buckshot created by gunpowder, also acting as a barter method.