I have placed you at the head of the Army of the Potomac. Of course I have done this upon what appear to me to be sufficient reasons. And yet I think it best for you to know that there are some things in regard to which, I am not quite satisfied with you. With this opening sentence in a two-page letter from Abraham Lincoln, Union general Joseph Hooker (1814 79) gained a prominent place in Civil War history. Hooker assumed command of an army demoralized by defeat and diminished by desertion. Acting swiftly, the general reorganized his army, routed corruption among quartermasters, improved food...