Gettysburg was the one to last of the major battles. To summarize the battle, it took three days. General lee had lost General Jackson not to long ago. The union had a lot more troops. Many people died. Lee ordered general Pickett to make his advance on the front lines of the union on a hill. That failed miserably. The union ended up taking the win on that battle.
The siege of Richmond. That is how the surrender started though. Grant gets Richmond. The union burns the city. Lee slips away and heads west. Grant follows. That day Grant gets a letter. The letter is lee's letter of surrender. Grant accepts. The point of surrender is the Appomattox courthouse. Grant is very generous in the terms. He let's the soldiers go.
On April 14, Booth went into Ford's Theater and got inches from the president head. He fired the shot which made Lincoln lump over on to his scared wife. He was rushed to a house across the street, but the bullet was fatal. Booth was later found in Georgia and was shot. Lincoln would be remembered as the first president to be assassinated in office.