Hemp has been grown for at least the last 12,000 years for fiber (textiles and paper) and food. It has been effectively prohibited in the United States since the 1950s.
George Washington and Thomas Jefferson both grew hemp. Ben Franklin owned a mill that made hemp paper. Jefferson drafted the Declaration of Independence on hemp paper.
During WWII, after US sources of "Manila hemp" were cut off by the Japanese, both the US Army and US Department of Agriculture promoted the "Hemp for Victory" campaign to grow hemp in the US.
Because of its importance for sails (the word "canvass" is rooted in "cannabis") and rope for ships, hemp was a required crop in the American colonies.
Henry Ford experimented with hemp to build car bodies. He wanted to build and fuel cars from farm products.
BMW, Mercedes and other cars utilize hemp materials in automobiles.
Much of the bird seed sold in the US has hemp seed, the hulls of which contain about 25% protein.
Hemp oil once greased machinery. Most resins, varnishes and paints used to be made out of flax and hemp oils.
Rudolph Diesel designed his engine to run on hemp oil.
Kimberly Clark (on the Fortune 500) has a mill in France which produces hemp paper preferred for bibles because it lasts a very long time and doesn't yellow.
Construction products such as medium density fiber board, oriented strand board, and even beams, studs and posts could be made out of hemp. Because of hemp's long fibers, the products will be stronger and/or lighter than those made from wood.
While industrial hemp and marijuana may look somewhat alike to an untrained eye, an easily trained eye can easily distinguish the difference.
Industrial hemp has a THC content less than 0.3% on a dry weight basis. You cannot obtain a psychoactive feeling from hemp.
If hemp does pollinate any nearby marijuana, genetically, the result will always be lower-THC marijuana, not higher-THC hemp. If hemp is grown outdoors, marijuana will not be grown close by to avoid producing lower-grade marijuana.
Hemp fibers are longer, stronger, more absorbent and more mildew-resistant than cotton.
Fabrics made of at least one-half hemp block the sun's UV rays more effectively than other fabrics.
Many of the varieties of hemp that were grown in North America have been lost. Seed banks weren't maintained. New genetic breeding will be necessary using both foreign and domestic "ditchweed," strains of hemp that went feral after cultivation ended. Various state national guard units often spend their weekends trying to eradicate this hemp, in the mistaken belief they are helping stop drug use.
A 1938 Popular Mechanics described hemp as a "New Billion Dollar Crop."
Hemp can be made in to a variety of fabrics, including linen quality.
The US State Department must certify each year that a foreign nation is cooperating in the war on drugs. The European Union subsidizes its farmers to grow industrial hemp. Those nations are not on this list, because the State Department can tell the difference between hemp and marijuana.
Hemp was grown commercially (with increasing governmental interference) in the United States until the 1950s. It was doomed by the Marijuana Tax Act of 1937, which placed an extremely high tax on marijuana and made it effectively impossible to grow industrial hemp. While Congress expressly expected the continued production of industrial hemp, the Federal Bureau of Narcotics lumped industrial hemp with marijuana, as it's successor the US Drug Enforcement Administration, does to this day.
Over 30 industrialized democracies do distinguish hemp from marijuana. International treaties regarding marijuana make an exception for industrial hemp.
Canada and the European Union now again allows the growing of hemp.
Hemp can be made into fine quality paper. The long fibers in hemp allow such paper to be recycled several times more than wood-based paper.
Because of its low lignin content, hemp can be pulped using less chemicals than with wood. Its natural brightness can obviate the need to use chlorine bleach, which means no extremely toxic dioxin being dumped into streams. A kinder and gentler chemistry using hydrogen peroxide rather than chlorine dixoide is possible with hemp fibers.
Hemp grows well in a variety of climates and soil types. It is naturally resistant to most pests, precluding the need for pesticides. It grows tightly spaced, out-competing any weeds, so herbicides are not necessary. It also leaves a weed-free field for a following crop.
Hemp can displace cotton which is usually grown with massive amounts of chemicals harmful to people and the environment. 50% of all the world's pesticides are sprayed on cotton.
Hemp can displace wood fiber and save forests for watershed, wildlife habitat, recreation and oxygen production, carbon sequestration (reduces global warming), and other values.
Hemp can yield 3-8 dry tons of fiber per acre. This is four times what an average forest can yield.
At a volume level of 81%, hemp oil is the richest known source of polyunsaturated essential fatty acids. It's quite high in some essential amino acids, including gamma linoleic acid (GLA), a very rare nutrient also found in mother's milk.
Hemp oil and seed can be made into tasty and nutritional products.