Mexicans celebrate independence day on September 16th, commemorating Miguel Hidalgo's "grito de independencia" in 1810 declaring Mexico's independence from Spain. September 13th honors the "Niños Heroes" who died defending Chapultepec Castle from U.S. forces in 1847. November 20th marks the start of the Mexican Revolution from 1910-1920, a rebellion against dictator Porfirio Diaz.