Dr. William Mayo and Dr. Charles Mayo were strong supporters of the U.S. military. Their advocacy led to the creation of the U.S. Army Medical Reserve Corps and their intensive work during WWI led to a remarkable advance in the quality of care provided to our soldiers, sailors, and pilots both during the war and far into the future. Many Mayo Clinic physicians and nurses played important roles in the military in WWI and in the conflicts that followed. The Department of Anesthesiology and Perioperative Medicine personnel has also contributed to the country’s armed forces military readiness and responses.