(A) bull run
(B) ** Lincoln formally announced the Emancipation Proclamation
(C) ** Lincoln announcing the EP changed one of the goals of the war
(D) ** Lincoln wanted a better job of General McClellan
EXPLANATIONS BELOW
Concept note-1: -Most importantly, Union victory at Antietam provided President Abraham Lincoln the opportunity he had wanted to announce the Emancipation Proclamation, making the Battle of Antietam one of the key turning points of the American Civil War.
Concept note-2: -George B. McClellan stopped Gen. Robert E. Lee’s first Confederate invasion of the North at the Battle of Antietam, the bloodiest day of warfare in American history. This narrow victory changed the course of the war.
Concept note-3: -After the war, McClellan served as an administrator for a number of engineering firms and, in 1878, was elected Governor of New Jersey. In his final years, the former general penned a defense of his tenure as Commander of the Army of the Potomac, but died before he could see it published.
Concept note-4: -The refusal to pursue the enemy at the close of the Antietam battle and for weeks afterwards, was the last straw for Lincoln, and he removed McClellan from power. Ultimately, McClellan was replaced by General Burnside as the new commander of the Army of the Potomac.