At the beginning of the Civil War, President Abraham Lincoln sought to bind important political leaders to the Union by appointing them as generals. The task was formidable: he had to find enough qualified officers to command a military that would fight along a front that stretched halfway across the continent. West Point hadn't graduated enough officers, and many of its best chose to fight for the Confederacy. Lincoln needed loyal men accustomed to organization, administration, and command. He also needed soldiers, and political generals brought with them their constituents and patronage...