The battles at Bull Run (1861 and 1862)
After the Union troops had a few months of training, they marched off to take the Confederate capital of Richmond, Virginia, and end the war quickly. At First Bull Run (1861) in Northern Virginia, the first battle of the war, one unit of Confederates held firm like a stone, earning their talented general the nickname "Stonewall" Jackson and buying the South enough time to win the fight.
The Union regrouped under Gen. George McClellan, who was good at organizing parades but not too good at actually fighting. About a year after Bull Run, McClellan lost the Peninsula Campaign (July 1862) to the Confederate Army under Robert E. Lee. Lee beat the Union again at Second Bull Run (August 1862) and headed into Union territory, only a few miles from Washington, D.C.
The battle at Antietam (1862)
In one of the two most important fights of the Civil War (the other was the battle at Gettysburg), Lee was turned back, barely, at Antietam (September 1862). Second Bull Run and Antietam showed that both sides could defend their own territory.
Britain and France might have been tempted to get involved on the Southern side, but Antietam (and their opposition to slavery) made them stay away.
The Emancipation Proclamation
Antietam also gave Lincoln the backing he needed to announce his plan to free the slaves in the states then fighting the Union. On New Year's Day, he officially issued the Emancipation Proclamation (1863). With the Union on record as fighting for the cause of freedom, average people in Britain and France made sure their governments wouldn't help the South. They had read Uncle Tom's Cabin (see "How Reading Led to Fighting" earlier in this chapter).
Question: What was the significance of the Battle of Antietam?
Answer: It helped convince England and France not to support the Confederacy, and it gave Lincoln the political strength to issue the Emancipation Proclamation.
Question: What was the most important immediate impact of the Emancipation Proclamation?
Answer: Issuing the Emancipation Proclamation showed that the North was fighting to end slavery, not just to preserve the Union. This increased support from ex-slaves and from foreign nations opposed to slavery.