The Church of the Firstborn (or the "LeBarón family") is a grouping of competing factions of a Mormon fundamentalist religious lineage inherited, adherents believe, by a polygamous family community that had settled in Chihuahua, Mexico, by Alma Dayer LeBaron Sr. by 1924.
Factions accepting leadership succession by some of Alma Dayer LeBaron Sr.'s sons self-describe as members of the Church of the Firstborn, without a legally formalized organization. What became over time the most substantial faction is that of Church of the Firstborn of the Fulness of Times, often shortened as the Church of the Firstborn, which was founded in September 1955 by three of Alma's sons, Joel, R. Wesley, and Floren LeBaron.
Since its founding, the order's most notable enclave has been within the jurisdiction of Galeana Municipality, Chihuahua. The LeBarons christened the LeBaron ranch Colonia Le Barón in the 1950s. Especially in more recent years, it is a minor segment of the order that engages in the practice of polygamy.
A substantial fraction of residents residing on and nearby order members' landholdings at Colonia LeBarón are not affiliated with the order, many of them identifying themselves on census reports as Roman Catholic and most of the remainder as evangélico (Protestant). A community that has inter-married but separate beliefs to Colonia Le Barón's is a three-hour drive away in rancho La Mora, 150 full-time residents strong, in Sonora.
Establishment
The LeBaron family, led by Alma Dayer LeBaron Sr., affiliated with the leadership of Mormon fundamentalist leader Joseph White Musser beginning in 1936. In June 1944, five of Dayer LeBaron's sons, Alma Jr., Benjamin T., Ervil, Ross Wesley, and Joel, were excommunicated from the Church of Jesus Christ of Latter-day Saints (LDS Church) for teaching and practicing plural marriage. For the next 11 years, a number of LeBarons associated themselves to various degrees with Rulon C. Allred's Apostolic United Brethren.
On December 9, 1957, Dayer's son Ben T. LeBaron said, wrote Samuel W. Taylor a letter saying that Ben believed himself to have received the birthright from his father and also believed Ben was to be the One Mighty and Strong of Joseph Smith's 1832 prophesy, sent to redeem LDS people from spiritual bondage.
Soon thereafter, various LeBarons declared that their family was possessed of especial priesthood keys of authority to a pre-millennial demi-messianic office or offices, in the restored earthly kingdom of God, with their ultimate leader said to possess this Right of the Firstborn becoming variously titled for example the One Mighty and Strong, the Presiding Patriarch in All the World, and so forth, the LeBarons' believing him the rightful heir of Joseph Smith Jr.'s mantle as leader of the early Latter Day Saints' Council of Fifty (via early Latter Day Saint Council of Fifty member Benjamin F. Johnson).
On September 21, 1955, Joel LeBaron and his brothers Ross and Floren visited Salt Lake City, Utah, and there organized the Church of the Firstborn of the Fulness of Times; Joel was ordained President of the Church, with Floren as first counselor in the First Presidency and Ross as head patriarch. Shortly thereafter, Joel reported being visited by nineteen former prophets, including Jesus, Abraham, Moses, Elijah, and Joseph Smith. In early 1956, the LeBaron brothers returned to Chihuahua. Their father Alma and brother Ervil became the fourth and fifth members of the new church; their mother Maud also eventually joined. Several months later, Ervil LeBaron published a pamphlet titled "Priesthood Expounded", which became a foundational text for the order.
A rival organizational structure for the order – which is named, in full, the Church of the Firstborn – additionally was formed in 1955 by Ross Wesley LeBaron, which Wesley thereafter led from its headquarters in Salt Lake City, Utah. Wesley believed he had been sent to prepare the way for the One Mighty and Strong, who would be "an Indian prophet" Joel and R. Wesley respectively claimed their especial "Firstborn order" priesthood lines of authority from Alma Dayer LeBaron, who had been ordained by Dayer's grandfather Benjamin F. Johnson, who had received these priesthood keys from Joseph Smith. LeBaron invited Allred and his followers to join their new order, but their invitation was rejected.