The 'little m.d.' or the 'big D.O.': the path to the California merger.

In the years following the American Osteopathic Association's sanctioning of the broad teaching of chemical and biological agents, osteopathic physicians moved closer to allopathic physicians with respect to diagnosis and treatment. In the 1930s, osteopathic colleges began to adopt standards and improve their basic science and clinical training, which allowed them to produce graduates who did substantially better in passing external examinations to become licensed as physicians and surgeons. Nevertheless, many state legislatures refused to grant DOs unlimited licenses and osteopathic physicians were unable to obtain medical commissions during the Second World War. In California, despite significant accomplishments on the social and legislative fronts, a growing number of osteopathic physicians believed that their DO degree and independent status as a separate medical profession was an impediment to achieving equality with their allopathic counterparts, and they worked toward a merger or amalgamation with their long-time opponents.