License plates, also known as vehicle registration plates, are required for every car in the United States these days, but when automobiles first started to appear on the road, there was no such thing. Although New York was the first state to require automobiles to have license plates in 1901, these plates were made by individual owners (with the owner's initials) rather than being issued by state agencies as they are in modern times. The very first license plates were typically handcrafted on leather or metal (iron) and were meant to denote ownership via the initials.

Source: ThoughtCo