The Mexican Revolution from 1910-1920 resulted in 1.7-2.7 million deaths and transformed Mexico. Dissatisfaction grew under the long dictatorship of Porfirio Díaz, who ruled from 1876-1911 and promoted economic development through foreign investment that mainly benefited the upper classes. In 1910, liberal reformer Francisco Madero challenged Díaz and launched the revolution. Over the next decade, various factions including those led by Pancho Villa, Emiliano Zapata, and Venustiano Carranza fought for power. By 1917, the revolutionary Constitution was adopted, establishing social and political reforms. However, fighting continued until 1920 when Alvaro Obregon consolidated power and enacted many revolutionary promises