During World War I, the US government denied DOs the same privileges that allopathic physicians (ie, MDs) enjoyed in terms of military service laws. Under the Selective Service Act of 1917,² young men in allopathic medical schools were furloughed so that they could continue their studies. They were not inducted into active duty for the US Army so long as they continued as medical students.³ Osteopathic medical students were not given the benefit of the medical student exemption law; thus the number of students at osteopathic medical schools decreased as osteopathic medical students and qualified osteopathic medical school candidates left for war.⁴ 

The Medical Corps of the US War Department refused to permit licensed DOs to take the examinations required for commission as a physician in the army. Furthermore, DOs who succeeded in passing the commission examination before this ruling was enforced, as Dr Dietrich did, were immediately denied commission. This practice was in direct opposition to President Woodrow Wilson's proclamation that asked every US citizen to “serve in the capacity for which his training and experience best fits him.”⁵ In an appeal for equality regarding examination and commission in the medical branch of the army, a hearing was convened in the spring of 1918 before the US House of Representatives' Committee on Military Affairs. 

In March 1918, George A. Still, DO, grandnephew of osteopathic medicine's founder Andrew Taylor Still, MD, DO, and vice president of the American School of Osteopathy, and G.W. Riley, DO, president of the AOA, appeared before the US Congress in hopes of enacting legal change so that osteopathic physicians could receive the same consideration under the law as allopathic physicians. Dr Riley, at the onset of his testimony, made it explicitly clear that the AOA was not pursuing an overhaul of the current legislation, but merely seeking equal treatment under the current laws of examination. Dr Riley announced:  

Dr Riley and the AOA fought for osteopathic physicians to have the same rights as other qualified medical doctors. The chairman of the committee, somewhat surprised by this pursuit, asked Dr Riley if he understood that entrance to the national examinations did not equate to entrance to service. Dr Riley replied with a rather candid and confident retort, as follows:  

If the AOA received its wish, laws would allow osteopathic physicians to complete the examinations but deny them from enlisting because of the nature of their degree. Even though an osteopathic physician may pass the required examinations and receive recommendation for commission to the Medical Corps, the surgeon general still had the ability to refuse service for any reason. Unfortunately, Surgeon General Gorgas found the idea of osteopathic physicians serving in the Corps to be disastrous. He stated, “The admission of osteopath physicians … to the Medical Corps would have practically unanimous opposition of the medical profession of this country and of all allied countries; would be regarded, and justly so, as lowering the standards, educational and professional, of our Medical Corps.”⁶ The conclusion of the congressional hearing was bittersweet. The AOA had won the battle for inclusion in the medical student exemption law as well as equal examination rights,¹ but the allopathic physicians in charge sent a clear message that no osteopathic physician would be commissioned for service in the medical branch of the US military. 

Despite the surgeon general's stance, 25 osteopathic physicians took the army medical examinations for commission in the Medical Corps. They answered the same questions, met the same educational standards as allopathic applicants, passed with excellent grades, and received unanimous support from the medical board for commissions. All 25 were rejected by the Medical Corps with the following statement: Even though President Theodore Roosevelt strongly supported the appointment of osteopathic physicians,^8(p8) Surgeon General Gorgas and the secretary of war stood by their decision, which remained for half a century. 

At the conclusion of World War I, the government's strong distrust toward physicians with osteopathic medical degrees remained, and DOs continued to be denied from the medical branch of the military. This denial united the AOA and DOs from around the country. With a strong organizational structure and increased resolve, the osteopathic profession was building the solid foundation it would desperately need during World War II. 

While World War II was a tragedy for all involved, the continued denial of osteopathic physicians only served to strengthen the profession's resolve. Osteopathic physicians, who as a group were exempt from the draft,⁹ were still barred from voluntary service in the medical branch of the military. This repudiation of service would lead to legislative and educational advances that allowed osteopathic medicine to reform, grow, and professionalize into the early framework of what it is today. 

As war preparation began in May 1941, President Franklin D. Roosevelt tasked the War Plans Division of the War Department General Staff to estimate the troop strength, including the number of physicians, necessary for the war. The report stated that there were roughly 176,000 physicians in the United States, of whom 50,000 would be needed to properly serve a troop base of around 8 million.¹⁰ Although the exact ratio of physicians to soldiers fluctuated from 1941 to 1945, the United States had roughly 45,000 physicians for a defense force of around 7.5 million during the war.^11(p67-69) Still unrecognized by the federal government as equal and legitimate physicians, osteopathic physicians were exempt from the draft yet still ineligible for commissioned service with the military medical corps. All physicians serving in the war were MDs. This mass exodus of 45,000 MDs left most of the country, especially rural areas, in a desperate physician shortage.¹² 

The final report on World War II published by the Medical Department of the US Army, entitled “Personnel in World War II,” highlights the lack of recognition given to the osteopathic medical profession during this time. The report only mentions osteopathic physicians in the following sentence under the heading “Other Minority Groups”:  

The military's efforts to restrict DOs from serving as physicians in the US military, perhaps influenced by efforts of many MDs to keep osteopathic medicine out of “their world,”^1,9,13 had unwittingly created the perfect situation for osteopathic medicine to grow exponentially. With the United States suddenly devoid of a quarter of its practicing physicians, DOs started caring for a majority of the patients left behind by the wartime MDs.⁹ Osteopathic physicians began taking a more prominent role as physicians and surgeons during the war, and it only continued as the war ended.¹⁴ 

World War II also had a tremendous impact on medical education for osteopathic physicians. During the World War II era, the osteopathic medical profession embarked on a journey to raise the educational standards of osteopathic medical schools. The level of training and commitment to improved education desired by the AOA, however, was difficult to achieve. Prior to World War II, osteopathic institutions were often crowded and had little to no laboratory or hospital access. Many of the osteopathic medical schools required very little in terms of candidates' education before entering the medical program; some schools did not even enforce the requirement of a high school diploma. In contrast, allopathic schools required a high school diploma and 2 years of undergraduate coursework.¹⁵ 

Because of these lax prerequisites, prior to the war, osteopathic medical schools appealed to students who wanted to become physicians but did not have the grades or pre-professional background to enter an allopathic medical school. Although the osteopathic medical schools had a strong financial framework, many of the schools struggled to provide a scientific education on a similar level to their allopathic counterparts. Even though the minimum pre-enrollment education standards were raised in 1940 to meet those of the allopathic schools, there seemed to be a disconnect between the excellence demanded by the AOA and the osteopathic medical profession and the education and training received at many of the osteopathic institutions. The Flexner report,¹⁶ a comprehensive study of medical education in the early 20th century, surveyed all 8 osteopathic medical schools and concluded its report on osteopathic medical education by saying, “Let it be stated, therefore, with all possible emphasis that not one of the eight osteopathic schools is in position to give such training as osteopathy itself demands.”¹⁵ If the osteopathic profession were to continue to survive and grow, the AOA had no choice but to make fundamental changes in the structure and quality of the osteopathic medical education system. 

In 1945, total enrollment in osteopathic medical colleges was merely 556, the lowest level in the 20th century.^9(p96) With tuition revenue dropping, the AOA set up the Osteopathic Progress Fund in 1943 to allow private practice osteopathic physicians to collectively donate millions of dollars to osteopathic colleges.^9(p97) After World War II, osteopathic medical schools made great strides in recruiting young students, and enrollment increased and surpassed prewar levels as returning veterans sought admission to DO programs.⁹ This increased number of applicants made acceptance into osteopathic colleges increasingly competitive. 

These fundamental changes to osteopathic medical schools implemented between 1935 and 1960 resulted in progress on both the medical front and the legal front. On state-required medical licensing boards, DOs went from 52% passing to 80% passing from 1942 to 1953, respectively, and by the early 1970s, the percentage of DOs passing such licensing examinations was not different from the percentage of MDs.¹³ Osteopathic medical schools now had an increasingly competitive applicant pool, a solid financial foundation, and most importantly, increased positive presence among the public because of their medical service on the home front in the absence of MDs. 

An important first for osteopathic medicine—perhaps the most important—took place in October of 1966. With a vote of 22-7, the Michigan State Senate voted to establish a state-sponsored osteopathic medical school.⁹ This vote was more than just a vote for a college—it signified the acceptance of osteopathic medicine by both society and government. Michigan State University College of Osteopathic Medicine was the first new osteopathic medical school in more than 50 years. Its formation and government support were a testament to the growth of the profession after World War II. Michigan State University College of Osteopathic Medicine was the first university-based osteopathic medical school, thus allowing osteopathic medical students and educators access to the Big Ten Conference, further access to federal grant money, and an increased standing in the academic medical community. Because of this outpouring of government support, along with the dramatic increase in educational standards and the public's increasing demand for osteopathic medicine, the number of osteopathic medical colleges had nearly tripled by 1980.⁹ 

The American Medical Association (AMA) had officially branded DOs as “cultists” in the 1920s, and the Joint Commission on the Accreditation of Hospitals specifically barred osteopathic physicians and surgeons from having staff privileges at member institutions.⁹ Furthermore, in 1923 the AMA had declared it dishonorable for MDs to consult with DOs.¹³ The policy became official in 1938 when the AMA forbade professional relationships between MDs and DOs.¹³ This policy led to the creation of patient clinics and separate osteopathic hospitals around the country. The postwar era marked the birth of federal financial support for osteopathic physicians and teaching centers as well. In 1951, the US Public Health Service awarded all 5 of the current DO schools renewable teaching grants previously designated for MD schools. Another federal program, The Hill-Burton Act (1946), allotted funds to osteopathic medical schools to aid in hospital construction.⁹ By the end of 1945, there were approximately 260 osteopathic hospitals around the country, 3 times the amount a decade earlier.⁹ More federal support was soon to follow. The Department of Health, Education, and Welfare supported the Health Professional Education Act (1963), which improved osteopathic medical schools and granted loans to osteopathic students, and the Health Manpower Training Act (1968) and Comprehensive Health Manpower Training Act (1971) continued to authorize special project money and improve student loans.^9(p148) 

The higher standards that were set forth because of World War II resulted in progress on the legal front. During the war, 9 new osteopathic specialty boards were established and 38 states had made DOs eligible for unlimited licensure. In a devastating blow to the anti-osteopathic arguments of MDs, a comprehensive review published by JAMA found that by 1970, no statistically significant difference existed between DOs and US-trained MDs in terms of licensure examinations.¹⁶ 

With the success of any professional organization, some of the most important factors are organization, public demand, and high standards. While the denial of service during World War I and World War II sparked a domino effect that drove many of the changes that led to increased standards for osteopathic medicine, the most important aspect of World War II was that it gave DOs a chance to interact with patients left behind by MDs serving in the war. Patient demand is an integral aspect of what drives medicine, and World War II gave osteopathic physicians the opportunity to present themselves to the US public. 

With the outpouring of government support for osteopathic physicians and the success and growth of the profession after World War II, it was difficult to continue denying osteopathic physicians who wanted to serve in the military. When the call for more than 2000 new physicians came in from the US Department of Defense for troops in Vietnam, Defense Secretary Robert McNamara instructed the armed forces to accept and commission qualified osteopathic physicians who volunteered for service.¹⁷ In 1967, for the first time, 111 osteopathic physicians were inducted to serve in the medical branch of the Army.¹⁷ Shortly after, in 1968, the Department of Defense designed and implemented a residency deferment program specifically for DOs.¹⁸ Today, osteopathic physicians serve throughout the military in every aspect of medicine. Dr Still's final message to the profession on his deathbed was never lost during this challenging journey, and even today, it is as clear as ever: “Keep it pure….”¹⁹