The U.S. state of Indiana first required its residents to register their motor vehicles and display government-provided license plates in 1913, with the law taking effect on July 1 of that year. In 1956, the U.S. states and Canadian provinces came to an agreement with the Automobile Manufacturers Association that standardized the size for license plates for vehicles, except those for motorcycles, at six inches in height by twelve inches in width, with standardized mounting holes. The 1955 (dated 1956) issue was the first Indiana license plate that complied with these standards