Somewhat related question, why did it take a constitutional amendment to ban alcohol, but not for marijuana?
They “banned” reefer with tax laws. You can sell it if you have a tax stamp...err o yea they wont sell any tax stamps. They just didn’t invent that until after prohibition.
You don’t need an amendment to make something illegal, although it is the toughest way to do it. That is just the way it was done with alcohol. An amendment is harder to overturn.