The Battle of Waterloo marked the final defeat of Napoleon. On June 22, 1815, four days after losing the conflict, Napoleon abdicated as emperor of France for the second and last time and was later exiled to St. Helena. The defeat brought an end to the Napoleonic Wars, a series of conflicts that had resulted in 23 years of recurrent warfare between France and other European powers. The Congress of Vienna, which was the settlement that followed the Napoleonic Wars, remade the map of Europe and set the stage for the emergence of Germany and Italy as unified states. The pressures of the Napoleonic Wars also likely prompted Napoleon to sell the Louisiana Territory to the United States.

Source: Britannica