There have been many studies of the generals who commanded the Union's victorious Army of the Potomac, but none has considered the corps, division, and brigade commanders (and their all-important staff officers) through the entire war—until now. Placing their actions in the social, political, military, and economic context of the day, this original and thought-provoking book examines in meticulous detail the command and performance of the brave and controversial officers of the Union's main fighting force.This study in command, the first of a multi-volume work, is based entirely on manuscript sources, many of which have never before been examined. As a result, the narrative and conclusions about the actions of many of the Union's prominent generals differ—often significantly—from traditional historical thinking. What emerges is a much different picture of these men and how their personalities influenced their command decisions and the political atmosphere that influenced and determined their military careers. The Army of the Potomac is about the leaders as men—their successes and failures commanding the Union's largest army.