Why was the Battle of Antietam a significant turning point in the Civil War and in American History? Objective Evaluate provisions of the Emancipation Proclamation, Lincoln's reasons for issuing it and its significance. Explain the causes of the Civil War and evaluate the importance of slavery as a principal cause of the conflict. Identify the turning points of the war and evaluate how political, military and diplomatic leadership affected the outcome. Determine the central ideas of a primary or secondary source and provide an accurate summary of the source distinct from prior knowledge or opi Duration: 90 Minutes.