I will split that enormous question in half: 1. Who is the foremost military historian of the American Civil War? And, 2. Who is the foremost historian of the American Civil War period? Your answers to both questions could conceivably be the same, but they needn't be. Choose your own definition of "foremost": most influential; most insightful; most knowledgeable, etc. Please give your reasons for your choice. I look forward to reading the opinions.