Commanders of the Army of the Potomac In his book on the Civil War, Commanders of the Army of the Potomac, Warren Hassler Jr. recounts the events that occurred between 1861 and 1865 during which Seven men were given the reins of the Army of the North Potomac and asked to lead the Union to victory. However, one of history's greatest commanders stood in their way; Robert E. Lee, and each one confronted this great general one by one and had a chance to make history. The first, Irvin McDowell, was considered in this book to be a great soldier in his own right, but a terrible leader who showed visible gaps in his preparation, tactics and strategy. He was the first to take control of the northern army. Not long after, in late May 1861, General Lee established a defensive position along the small Bull Run stream located in Manassas. During the Battle of Bull Run, McDowell was crushed by Confederate generals Joseph E. Johnston and Pierre Beauregard due to poor planning, and it became apparent that this would, in fact, not be a short-lived war. Next was the most popular and perhaps greatest of the commanders, George B. McClellan. After the embarrassing defeats at Bull Run, he masterfully reorganized and disciplined the AOP as he himself displayed exceptional military presence and steadily increased his knowledge of offensive tactics. From the spring of 1862 until July of that year, General McClellan succeeded in driving the Confederates from West Virginia, and was approaching the southern capital of Richmond when General Jeb Stuart under Lee surrounded and defeated McClellan's forces, which were rejected. and finally it was held at Malvern Hill during the Seven Days' Battle. During this period of time, there was some shift in control and the AOP was placed in the arms of General John Pope. This book considers Pope one of the most pathetic leaders of the Civil War as he made a mistake and changed his ways during the second battle at Bull Run and sacrificed his men needlessly. Meanwhile, McClellan missed the opportunity to unbalance the Confederates after learning of Lee's plans, but stalled and hesitated for a day, giving Southern reinforcements ample time to arrive and regroup together, and the North escaped with a slight victory only after Lee decided it would be wise to withdraw his forces.