The AMA's first Code of Medical Ethics

By the 1840s the United States had more than 30 medical colleges, chartered freely by state legislatures and dependent on student fees, and their diplomas were accepted as licenses to practice. In February 1845 Nathan Smith Davis persuaded the New York State Medical Society to call for a national convention on medical education. About 100 delegates from 16 of the 26 states met at New York University on 5 May 1846 and resolved that the profession should form a national association and be governed by a single code of medical ethics.

On 5 May 1847 about 250 delegates from at least 40 medical societies and 28 medical schools in 22 states met at the Academy of Natural Sciences in Philadelphia. They adopted a constitution for the American Medical Association, which dates its founding to 7 May 1847, and recommendations on preliminary education for students and a uniform standard for the MD degree.

The ethics committee, reporting through John Bell with Isaac Hays, both of Philadelphia, found that local societies' codes were all based on Thomas Percival's Medical Ethics of 1803, and kept Percival's words wherever they served; a few sections came from Benjamin Rush. The code set out duties of physicians to patients and of patients to physicians, of physicians to one another, and between the profession and the public. Physicians were to keep patients' secrets even after their care ended, to treat fellow practitioners and their families without charge, and, when pestilence prevailed, to keep working even at the risk of their own lives. Patients owed prompt obedience to prescriptions. No one whose practice rested on an exclusive dogma was to be accepted as a colleague in consultation.

The association later confronted its record on race. In 2008 the AMA published in JAMA an examination of racism and racist practices in the organization since its founding and made a formal apology for its past discrimination against Black physicians, and in 2021 it removed a bust of Davis from public display, acknowledging his role in blocking integration.