This wonderful short treatise is not by just any professor of surgery or former army doctor. William Williams Keen was America’s first brain surgeon, was brought in to see Franklin Delano Roosevelt when he was paralyzed by polio, and worked closely with six American presidents. If you read one book about Civil War medicine, whether you are a medical professional or layperson, this is the one. Keen’s raw and compelling memories as a young field surgeon are unmatched.