This lecture stresses that either side could have won the war and offers a careful analysis of the strengths and weaknesses each brought to the conflict. There was early strategic planning on both sides; the lecture discusses some crucial battles of the first year's fighting. The conflict mushroomed from a limited military contest at the time of First Bull Run in July 1861 into a massive struggle by the time of Shiloh and the Seven Days battles in the spring and early summer of 1862.