From BlackPast.Org:
The involvement of African Americans in medicine in the Civil War era is an untold chapter in our history. Up to that time most practitioners had learned medicine by apprenticeship but this began to change in the early Nineteenth Century. James McCune Smith was the first African American to obtain a medical degree when, in 1837, he was graduated from the University of Glasgow in Scotland. In 1847 David James Peck was the first to receive a medical degree in the United States. By the end of the Civil War at least 22 African Americans had obtained degrees and were practicing medicine. At least twelve of these physicians served with the Union Army.
Three men were commissioned officers while the remaining nine served as acting assistant surgeons (contract physicians). Alexander Thomas Augusta from Norfolk, Virginia, was unable to obtain admittance to a United States medical school so he went to Ontario, Canada. There he was successful in gaining admittance to Trinity College, Ontario University. In 1860 he became the first person of African ancestry to receive a medical degree in Canada. He received his commission as a surgeon (with the rank of major) in April 1863 in the 7th United States Colored Infantry (known popularly by the initials, USCT, for U.S. Colored Troops). Augusta was the first African American to obtain this rank in the U. S. Army. At the end of the war he was brevetted to lieutenant colonel, a promotion for meritorious service. When Howard Medical College opened in 1868, he was the only African American on its original faculty. Nine years later he left the medical school for private medical practice in Washington, D.C. Augusta died in 1890 and was the first African American officer to be buried in Arlington National Cemetery.
More here. (Note: Throughout February, at least one post will be dedicated to honor Black History Month)