Fifty years after the Battle of Gettysburg turned quiet Pennsylvania fields into a brutal crossroads of war, something extraordinary happened. The veterans came back. Not to fight. Not to argue. But to remember. To stand together on the same ridges and fields where they had once tried to kill each other, and shake hands instead. More than 53,000 of them, Union and Confederate, answered the call for a reunion that would become one of the largest peaceful assemblies of former enemies in history.