The Durham-Humphrey Amendment explicitly defined two specific categories for medications, legend (prescription) and over-the-counter (OTC). This amendment was co-sponsored by then Senator (and later Vice President) Hubert H. Humphrey Jr., who was a pharmacist in South Dakota before beginning his political career. The other sponsor of this amendment was Carl Durham, a pharmacist representing North Carolina in the House of Representatives. Legend drugs must be dispensed with direct medical supervision, but over-the-counter drugs can be purchased and used without a prescription.