Constitution of 1917 also forbade the existence of monastic orders (Article 5) and religious activities outside of church buildings (which became government property), and mandated that such religious activities would be overseen by government (Article 24). On 14 June 1926, President Calles enacted anticlerical legislation known formally as The Law Reforming the Penal Code and unofficially as Calles Law. His anti-Catholic actions included outlawing religious orders, depriving the Church of property rights and depriving the clergy of civil liberties, including their right to a trial by jury in cases involving anti-clerical laws and the right to vote. Catholic antipathy towards Calles was enhanced because of his vocal anti-Catholicism. Due to the strict enforcement of anticlerical laws, people in strongly Catholic states, especially Jalisco, Zacatecas, Guanajuato, Colima and Michoacán, began to oppose him, and this opposition led to the Cristero War from 1926 to 1929, which was characterized by atrocities on both sides. Some Cristeros applied terrorist tactics, including the torture and killing of public school teachers, while the Mexican government persecuted the clergy, killing suspected Cristeros and supporters and often retaliating against innocent individuals. A truce was negotiated with the assistance of U.S. Ambassador Dwight Whitney Morrow. Calles, however, in violation of its terms did not abide by the truce and he had approximately 500 Cristero leaders and 5,000 other Cristeros shot, frequently in their homes in front of their spouses and children. Particularly offensive to Catholics after the supposed truce was Calles' insistence on a state monopoly on education, suppressing Catholic education and introducing socialist education in its place: "We must enter and take possession of the mind of childhood, the mind of youth." Persecutions continued as Calles maintained control under the Maximato and did not relent until 1940, when President Manuel Ávila Camacho took office. Attempts to eliminate religious education became more pronounced in 1934 through an amendment of Article 3 of the Mexican Constitution, which strived to eliminate religion by mandating "socialist education", which "in addition to removing all religious doctrine" would "combat fanaticism and prejudices", "build[ing] in the youth a rational and exact concept of the universe and of social life". In 1946, socialist education provisions were removed from the constitution and new laws promoted secular education. Between 1926 and 1934 at least 40 priests were killed. Where there were 4,500 priests operating within the country before the War, in 1934 there were only 334 priests