However, Mexico's political climate gradually worsened. Porfirio Diaz, Mexico's longtime dictator, lost control of the government and revolution ensued. Shortly after serious fighting began in Mexico City in 1913, the church's First Presidency authorized the Pratts and the American missionaries to return to the United States. The Pratts moved to Salt Lake City in September 1913. Two years later, the First Presidency again instructed the Pratts to move, this time to Manassa, Colorado, and establish missionary work among Mexicans in the United States. After five years, in November 1918, church leaders moved the mission headquarters to El Paso, Texas, making it closer to the center of the vast mission territory.