U.S. pharmacy practice has multiple roots, including herbal remedies and home medical knowledge, which European settlers brought from their home countries. As in many European countries, the boundary between medical and pharmacy practice was not as distinct in Colonial America and the United States in the 17th through early 19th centuries as it is today, and physicians as well as apothecaries and druggists often sold medicines to patients.

Pharmacy knowledge and professionalization increased in the 19th century, and the modern distinction in roles between physician and pharmacist, with the former writing prescriptions and the latter filling them, became more common during this period. Another important milestone for pharmacy was the creation of the Massachusetts Pharmacopoeia in 1808 and the Pharmacopoeia of the United States in 1820; ...