The U.S. Civil War ended.
The date: April 9, 1865. The place: the house of Wilmer McLean at the village of Appomattox Court House Virginia. The formal surrender took place at the court house on April 12. When it was over Confederate soldiers were allowed to keep their horses and go home. Confederate officers could retain swords and sidearms.
The toll: 500,000 dead.
It would be exactly one year later on April 9, 1866 that Congress passed a law (over the veto of President Andrew Johnson) granting Blacks the rights and privileges of U.S. citizenship. It was this act that formed the basis for the 14th Amendment.