The Mormon Church has been proselytizing in Mexico since 1875. In 1882 the Edmunds Act outlawing polygamy in the US was passed US Congress making the practice of plural marriage a felony. Over 1,000 polygamists were fined and/or jailed. In the Sierra mountains in Chihuahua in Northern Mexico, Mormon polygamist colonies were set up to avoid US laws to practice multiple marriage and be left in peace.
Junius Romney became president of the Juarez colony in 1908. When the Mexican Revolution occurred in 1911, the Mormons tried to stay neutral and were left alone, promised safety by the rebels. When President Taft ordered all American living in Mexico to leave in March 1912, resentment by rebel forces threatened the safety of the colonies. In July 1912 Junius Romney met with rebel general Jose Inez Salazar and was told that all guarantees of safety were lifted and that the Mormons must deliver up their arms. “If your guns and ammunition is not delivered to us, we will attack you. We will consider you as our enemy and declare war on you.” In July 1912 Junius Romney directed that the polygamist colonists in Mexico would flee to the US. 4 colonies consisting of over 4,000 men, women and children crossed over into Texas heading for El Paso.On August 30, 1912 Rebel General Salazar made good his threat and began a campaign of forcing American residents to leave Mexico, ordering the residents of the American Mormon settlement in Colonia Morelos, in the State of Sonora, to leave the country within two weeks.
American Mormons Flee Mexico by train – 1912