"Samuel Thomson, born in New Hampshire in 1769 to an illiterate farming family, had no formal education, but he learned the elements of botanical medicine from a "root doctor," who he met in his youth. Thomson sought to release patients from the harsh bleeding or purging regimens of regular physicians by offering inexpensive and gentle medicines from their own fields and gardens. He melded his followers into a militant corps of dedicated believers, using them to successfully lobby state legislatures to pass medical acts favorable to their cause.

 "John S. Haller Jr. points out that Thomson began his studies by ministering to his own family. He started his professional career as an itinerant healer traveling a circuit among the small towns and villages of Maine, New Hampshire, and Massachusetts. Eventually, he transformed his medical practice into a successful business enterprise with agents selling several hundred thousand rights or franchises to his system. His popular New Guide to Health (1822) went through thirteen editions, including one in German, and countless thousands were reprinted without permission.

"Told here for the first time, Haller's history of Thomsonism recounts the division within this American medical sect in the last century. While many Thomsonians displayed a powerful, vested interest in anti-intellectualism, a growing number found respectability through the establishment of medical colleges and a certified profession of botanical doctors." (publisher)