The Treaty of Armistice and Regularization of War signed on November 25 and 26, 1820 between the president of the Republic of Colombia, Simón Bolívar and the Chief of the Military Forces of the Spanish Kingdom, Pablo Morillo, is the precursor of the International Humanitarian Law. The Treaty of Guadalupe Hidalgo, signed and ratified by the United States and Mexico in 1848, articulates rules for any future wars, including protection of civilians and treatment of prisoners of war. The Lieber Code, promulgated by the Union during the American Civil War, was critical in the development of the laws of land warfare.See, e.g.,
