The Thomsonian movement, founded by Samuel Thomson, was the first major challenge to the therapies and the social and economic standing of the orthodox medical profession in the United States. In the late-eighteenth or early-nineteenth century, many states chartered a state medical society with power to administer a licensing law that placed at least a nominal penalty on practicing without a license. However, in the 1830s and 1840s, under pressure by proponents of the Thomsonian system, almost all legislatures reversed themselves and removed all restrictions on medical practice. This paper reexamines the rise and fall of medical licensing using Connecticut as a case study. Antebellum legislative controversies over licensing have never been described in detail at the state level--where the drama took place--integrating the perspectives of both the medical regulars and Thomsonian botanical physicians, and state politics. Connecticut is a particularly useful case study because, except for New York, its seven-year battle from 1836 to 1842 over the medical society's charter was the most protracted in the country. How was the campaign structured? To what extent did the licensing restrictions matter? What role did the state-level Democratic party play? Thomsonianism in Connecticut, I suggest, was more professionalized and conservative than historians have often portrayed this movement. This account shows that the state's Thomsonian physicians were not anti-professional or opposed to education, but rather used the politics of the antebellum era to challenge the medical law and legitimize themselves as an alternative form of practice.