The president had to make a decision on whether to let the confederates leave the union or force them to stay. In the end, he was forced to make a choice when confederates attacked Fort Sumter in Charleston, South Carolina. This started the Civil War.
The Emancipation Proclamation January 1863
Four score and seven years ago...
Union Troops stumbled upon General Lee's plans. The union use the plans to attack, but no one was gaining grounds. It was a very bloody battle. Lee withdrew to Virginia, but the general didn't follow, missing a opportunity. Even though it was a union victory, Lincoln still fired him.
Appomattox Court House April 1865
Lee's men had stumbled on Union troops in Gettysburg, Pennsylvania. Union troops gained the higher ground. The confederate retreated, but there was no union counterattack. The Battle of Gettysburg was a turning point in the Civil War. This battle inspired great heroes like William Carney in the Civil War..
Assassination of Lincoln April 1865
On September 22, after the victory at Antietam, he issued the preliminary Emancipation Proclamation, declaring that as January 1, 1863 all slaves in rebellious states are declared free.
Lee and his army was trapped near a small town in Virginia. His numbers were too small to continue fighting. Ulysses G. Grant(the union general) led the troops. On April 9, 1865, Lee surrendered.
Five days after General Lee surrendered , the president was assassinated by John Wilkes Booth. This took a huge toll on the U.S and started the Reconstruction Era.