Being a non-psychoactive form of cannabis, its uses were entirely industrial. One need not be a libertarian to recognize that the prohibition of hemp ranks among the most absurd and pointless laws our government passed in the twentieth century.
Prior to the War on Drugs, the United States had a long history of hemp production, going all the way back to the colonial era and Britain even before that. Before governments arrested people for growing hemp, they used to fine farmers for not growing it. In the sixteenth century, King Henry VIII and Queen Elizabeth I fined English farmers who failed to contribute to the country's hemp industry. In 1673, King Charles II instructed the Royal Governor of Virginia to impose the edict on the Virginia colonists.1 Hemp was particularly valuable to the Royal Navy, which used it for uniforms, ropes, and sails, among other things.
It is relatively common knowledge that several Founding Fathers of the United States grew hemp. Occasionally, pro-marijuana activists will cite this as evidence that the Founders smoked cannabis, but there is no evidence to support this, and the recreational or medicinal use of marijuana did not come to the United States until the nineteenth century. But for industrial purposes, figures as prestigious as George Washington grew hemp, following the instructions detailed in the pamphlet "A Treatise of Hemp-Husbandry," authored by Edmund Quincy, a cousin of President John Adams.