Motorcycle Helmet Law
To make motorcycle helmet use more widespread, in 1967 the federal government required states to implement motorcycle helmet law in order to be eligible for various federal safety programs and highway construction funding. Thusly motivated, by the early 1970s nearly all states had enacted universal motorcycle helmet laws.
In 1968, Michigan was the first state to repeal the legislation, ushering in a pattern of repeal, reenactment and amendment of motorcycle helmet law.
Currently, all states, save four, require some riders (persons under 15, 18, 19 or 21) or all riders to wear motorcycle helmets.