Carranza established a strong government in Mexico from 1917-1920 to confront economic, political, social and military crises, but he was later assassinated. Obregon and Calles then led the governments in the 1920s, with Calles remaining president until 1934 and continuing Obregon's policies. Calles enforced anti-clerical articles of the constitution, angering Catholic groups and sparking the violent Cristero Rebellion. He also created the PNR political party, later renamed the PRI, to consolidate power. During the Maximato period from 1928-1934, Calles continued to direct politics through puppet presidents. Cardenas then nationalized Mexico's oil industry in the late 1930s, angering the United States and