The reason the goverment made tax stamps is because it was the only way they could legally make marijuana illegal. The idea came from baning the sale of automatic tommy guns by only making a limited amount of stamps. Normls is wrong when they say the reason for the tax is so they can charge you with tax evasion. The history channel has an entire series called hooked: Illegal drugs and how they got that way, Marijuana where they explained this and how anslinger used this to ban marijuana