May 12 - 1865 - The Battle of Palmito Ranch
The Battle of Palmito Ranch, in all reality, should have never happened, as it took place a month after Robert E. Lee surrendered to Ulysses S. Grant, in a location that never saw serious fighting. Yet it was notable because it was the very last battle of the American Civil War and saw the very last casualty of the conflict, Private John J. Williams of Indiana. It has been said that the Battle of Palmito Ranch began because it was one last chance at glory for Union troops stuck along the Mexican border in Texas. One peculiarity of the Battle of Palmito Ranch was that it featured black troops on the Union side fighting against Mexican troops on the Confederate side. Still, the battle was between just a few hundred troops, and there was one death and minimal casualties. Essentially, the Confederate troops held off a small offensive maneuver by the Union troops near them. So it's only real notability came from being a Confederate victory in the last battle of a war that Union won. Of course, the outcome of the Battle of Palmito Ranch did nothing to change the outcome of the war, and it was maybe just a Pyrrhic victory.