Different states in the US follow different motorcycle helmet laws that cater to their own residents and constituents. Motorcycle helmet law has been instituted to provide safety and protection to motorcycle riders from different states.
But the helmet law being followed in one state may not be the same as those followed in another. There are even other states that do not have their own laws governing the proper use of motorcycle helmets. There are currently 4 states that do not have their own motorcycle helmet law.