June of 1950 found the US forces poorly prepared to stop North Korean forces rolling into South Korea. First encounters scattered American soldiers and presented unique challenges for care of the casualties; battalion doctors and medics hustled the wounded along, sometimes themselves trapped, captured, or killed. Finally, within the Pusan perimeter American and South Korean resistance stiffened. It was in this defensive position the first Mobile Army Surgical Hospitals (MASH) were deployed far forward-heretofore simply a paper concept. MASH units performed magnificently, resuscitating and evacuating gravely wounded American and South Korean casualties, ushering in a new dimension to combat casualty care.