Seat belts Question?

Some guy wants to know what year did all cars start coming with seat belts installed.
 
He says 1962 and I say 1966.
 
I can't find a clear answer on the internet.
 
DOES ANYBODY KNOW?

I thought Volvo or Saab came up with the idea late 50s but no idea when America got with the program.

I keep thinking about Green Acres with Mr Haney driving a truck with rope for a seatbelt...

A quick Wiki search yielded this:

"Most seat belt legislation in the United States is left to the states. However, the first seat belt law was a federal law,Title 49 of the United States Code, Chapter 301, Motor Vehicle Safety Standard, which took effect on January 1, 1968 that required all vehicles (except buses) to be fitted with seat belts in all designated seating positions.[1] This law has since been modified to require three-point seat belts in outboard seating positions, and finally three-point seat belts in all seating positions. Initially, seat belt use was not compulsory. New York was the first state to pass a law which required vehicle occupants to wear seat belts, a law that came into effect on December 1, 1984."

From:  Wiki Article