Eight O Seven 807
Eight O Seven 807, a law that allows fabrics cut in the United States, garments assembled in Mexico, the Caribbean and Central American countries. And return to the United States with tariff assessed on added value (sewing). It was a highly controversial law its opponents argue that the provision exports jobs from Americans to other nations and free trade.
Nevertheless, another reason was that Hemp was imported from Mexico and was a direct threat to the US cotton Industry. Industrial hemp was banned by law in 1937 (Marihuana Tax Act) and added tax on anyone who dealt commercially with hemp. The passing of the act was purely economic and involved people such as Andrew Mellon, Randolph Hearst and the DuPont family. More about hemp fibre and its history USDA.org