The Cristero War (also known as the Cristiada) of 1926 to 1929 was an uprising and counter-revolution against the Mexican government of the time, set off by religious persecution of Catholics, specifially the strict enforcement of the anti-clerical provisions of the Mexican Constitution of 1917 and the expansion of further anti-clerical laws. Regarding this period, recent President Vicente Fox stated, "After 1917, Mexico was led by anti-Catholic Freemasons who tried to evoke the anticlerical spirit of popular indigenous President Benito Juárez of the 1880s. But the military dictators of the 1920s were a more savage lot than Juárez."

After a period of peaceful resistance, a number of skirmishes took place in 1926. The formal rebellions began on January 1, 1927 with the rebels calling themselves Cristeros because they felt they were fighting for Christ himself. Just as the Cristeros began to hold their own against the federal forces, the rebellion was ended by diplomatic means, brokered by the U.S. Ambassador Dwight Whitney Morrow.