Chumash Indians were using highly worked shell beads as currency 2,000 years ago

[wnylib]

2. The Native people of New England

used shell beads as currency, too. I don't have any dates for how far back that currency use goes. The early British settlers at Plymouth and Massachusetts Bay also used shell beads as currency when making deals with the Native people.

Among the tribal nations of the Iroquois Confederacy, shell beads (wampum) were strung into images to represent political agreements with each other, and later, to commemorate treaties with the colonies. Individuals who made deals with each other also used strings of colored shell beads to seal their deals, with a witness, and regarded the bead string the way we would regard a contract.

The unifying agreement between the 5 nations (later, 6) of the Iroquois Confederacy, known as the Great Law of Peace, is "recorded" in a wampum belt that symbolizes the member nations with a sacred pine in the center representing the location of the Onondaga nation (keeper of the council fire) where delegates met for confederacy business.

https://en.m.wikipedia.org/wiki/Great_Law_of_Peace

ON EDIT: Scroll down for an image of the wampum belt that symbolizes the foundation of the confederacy. It served as a memory aid for recitation of the foundation story during gatherings of elected delegates from each tribal nation member - a constiturion.