"The US Army Medical Department has an extensive and illustrious history. Brief historical highlights include maintaining one of the oldest regiments within the Army, providing the antecedent organization for the Army Reserve system, and establishing some of the first methods to capture lessons learned. Preserving, interpreting, and publishing the history of the US Army Medical Department, is the mission of the Office of Medical History. Operating almost continuously since 1862, forms of the Office of Medical History have endured numerous organizational changes. Despite the different incarnations, the Office of Medical History continues to record the activities of the US Army Medical Department and provide Soldiers and the general public with a variety of historical products."
Many of the official histories of the U. S. Army Medical Department from its inception to the near present are available at this link.