Prohibition began in the 1920s thanks to William Randolph Hearst who wished to use the many acres of forests that he owned to produce paper from wood-pulp. He had stitched up a deal with Dupont who had patented a process to do so and the only thing left to do was to put marijuana (a new word invented for the purposes of demonising cannabis) growers out of business - hence the Marijuana Tax. Cotton growers were also happy to jump on the bandwagon.
It could be argued that hemp was responsible for puffing the "Great" into Britain. All rope, sails and paper required to sustain the British Empire were made from hemp. During the reigns of Henry VIII and Elizabeth I it was possible to be busted for not producing one's tithe of hemp for the realm. What a turn around.
S J GLAZZARD