California Resale Royalty Act
The California Resale Royalty Act (Civil Code section 986), which went into effect on January 1, 1977, entitles artists to a royalty payment upon the resale of their art if the transaction takes place in California or the seller is based in the state. It was the only law of its kind implemented in the United States.
Source: Wikipedia — California Resale Royalty Act (CC BY-SA 4.0)