Battle of Chancellorsville, VA (04/30-05/06, 1863)
ARM OF STONEWALL JACKSON MAY 3, 1863.
Siege of Port Hudson, LA (05/22-07/09, 1863)
Battle of Gettysburg, PA (07/01-03, 1863)
Union General Hooker battled against Lee, who strategically divided his army in the face of a much larger troop and brought about a significant Confederate victory. Yet it is also significant because Stonewall Jackson was mortally wounded and died after this battle.
Battle of Fort Stevens, DC (07/11-12, 1864)
In order to aid Grant who was besieging Vicksburg, Union general Banks besieged Port Hudson for 48 days until the Confederate commander surrendered the port. It is significant because it effectively ended Confederacy's access to Mississippi River.
Battle of Atlanta, GA (07/22, 1864)
Lee ordered the futile Pickett's Charge, and the battle turned out to be an important Union victory. It is important because it involves the largest number of casualties of the entire war, and prompted Lincoln's Gettysburg Address.
Battle of Appomattox Court House, VA (04/09/1865)
The Confederacy led skirmishes around Fort Stevens and Union won with their strong defenses. It is important because Lincoln himself went to observe the battle, and the guy standing next to him got shot.
To seize the rail and supply center of Atlanta, Union forces commanded by William Tecumseh Sherman overwhelmed and defeated Confederate forces defending the city. It is important because Sherman utilized the modern idea of total war to win the campaign.
Lee launched a last-ditch attack to break through the Union forces to his front due to an erroneous estimation of Union troops. At last he had no choice but to surrender. It is important because it concluded the Civil War with Union victory.