The correct answer is the Battle of Antietam.
The Battle of Antietam was the bloodiest battle in the Civil War. Roughly 22,000 were killed. However, this battle gave the Union a victory in terms of strategic location. This "victory" gave Lincoln the confidence to issue the Emancipation Proclamation. The Emancipation Proclamation stated that slaves "in all rebellious states" (meaning the Confederacy). This did not sit well with the Confederates and practically all the states ignored it since they considered themselves part of another country anyways.
Answer:
While Churchill equals frequently credited with getting arisen this passage “ metal blind, ” he may, ironically plenty, get gone this period from counting Schwerin von Krosigk, that foreign minister of Germany in the last days of the war, who, the Times reported, had warned in a radio broadcast a few days before VE Day, “ in the East the iron curtain behind which, unseen by the eyes of the world, the work of destruction goes on, is moving steadily forward. ”
The Second Battle of Bull Run (Second Manassas).