Blockade of southern supply lines
Meanwhile, the North tightened its Anaconda Plan blockade to cut off Southern supplies. Southerners had figured that Britain would have to help them because something like one out of five jobs in Britain was tied to Southern King Cotton. Even though some British working people went unemployed and hungry, the British refused to help. The Northern states shipped Britain extra food; they had plenty to share.
The South tried to break the blockade with a homemade iron-sided ship called the Merrimack. Just in time, a Union ironclad arrived to fight. The Monitor and the Merrimack (1862) fought to a tie. After this first fight between metal ships, it was clear that warships of the future would be made out of steel, not wood.
The battles of Fredericksburg (1862) and Chancellorsville (1863)
The Union lost badly at Fredericksburg (December 1862) by attacking an unbeatable Southern entrenchment and at Chancellorsville (May 1863). They were suckered by a brilliant flank attack by Lee. Up to that time, the Union commanding generals (McClellan, McDowell, Burnside, Hooker) deserved a grade of about F+.
The battles at Gettysburg and Vicksburg (1863)
Lee was feeling his oats and decided to have another go at invading the North. At Gettysburg (July 1863) in Pennsylvania, he attacked Union troops who would not be moved. For three days of ferocious fighting, the Union held. The battle was very close; the South had peace commissioners ready to take the Union's surrender. Instead, Lee's army was forced to retreat to Virginia. Gettysburg, the South's last real chance to win the Civil War, joined Antietam as the other key battle of the conflict.
Question: What were the two key battles of the Civil War?
Answer: Antietam, where the North held the line against the South, and Gettysburg, where the South was defeated in Northern territory.
The day after Gettysburg, General Ulysses S. Grant took the Confederate fortress at Vicksburg (1863), splitting the South at the Mississippi River. With the twin victories at Gettysburg and Vicksburg, Britain and France even stopped taking Southern money to build them warships. The Confederacy was on its own. Union General William Tecumseh Sherman marched across the Confederacy from Atlanta to the sea (1864), leaving a 60-mile-wide path of destruction and freeing 25,000 slaves. His tactics were brutal, but they helped shorten the war and save lives. He said, "War is all hell."