Delta-9 THC can be legal and illegal. Let's break down the reasons and simplify. As per the 2018 Farm Bill & USDA hemp growing regulations. Delta-9 that is extracted from compliant hemp/cannabis plants containing a total content of <0.3% THC at dry weight, is 100% legal, Federally. Some states are 'grey' on some hemp derived products, so this can vary State to State. Hemp derived compliant Delta-9 THC can be legally shipped across state lines. If any hemp derived product contains greater than <0.3% THC, they are deemed federally illegal and carry the penalty associated with "marijuana" federal law. Delta-9 THC extracted from legally defined marijuana, is Federally illegal and can only be sold in medical or recreational legal States, and must be sold as Marijuana products. These products are also void of the legal ability to ship across state lines.