The Controlled Substances Act of 1970 classified all forms of cannabis including hemp as a Schedule I drug. This makes it illegal to grow in the United States except for certain licensed research. This is one reason why the USA is forced to import hemp from other countries as long as it contains 0.3% THC which is the regulation for hemp cultivation.
5/29/2018 – These laws and regulations are currently and very quickly changing so please research further for updated information if you happen upon this post sometime in the future.