George Brinton McClellan

After the Union army’s defeat at the First Battle of Manassas on July 21, 1861, President Abraham Lincoln appointed General George McClellan to command federal operations in Virginia. Within weeks, McClellan transformed a demoralized volunteer army into a disciplined fighting machine: the Army of the Potomac.

But achieving victory required engaging the enemy in battle, and in this McClellan procrastinated, much to Lincoln’s exasperation. Lincoln wrote McClellan in April 1862, “it is indispensable to you that you strike a blow. I am powerless to help this . . . you must act.” Tension between Lincoln and McClellan grew further when the general, who joined the fight solely to preserve the Union, urged the President not to issue the Emancipation Proclamation. After he failed to pursue Robert E. Lee’s army following the Union victory at the Battle of Antietam in September 1862, Lincoln relieved McClellan of his command.