Mission San Xavier del Bac was established in 1692 by
Eusebio Francisco Kino, who founded a chain of
Spanish missions in the Sonoran Desert. A
Jesuit of Italian descent, Kino often visited and preached in the area, then the
Pimería Alta colonial territory of the
Viceroyalty of New Spain. The "little hill" is believed to be that southeast of San Xavier del Bac. The location was vulnerable to
Apache raids, and construction was interrupted until 1756, when it resumed under
Alonso Ignacio Benito Espinosa. By 1763 the building was sufficiently complete that the missionaries could hold services inside it, although a poorly prepared foundation led to architectural issues. borrowed from a
Sonoran rancher, they hired architect Ignacio Gaona, who employed a large workforce of O'odham to create today's church. With the
Gadsden Purchase in 1853, the site of San Xavier became a part of the United States and the new
Territory of Arizona. The church was re-opened in 1859 when the Santa Fe Diocese added the mission to its jurisdiction. It ordered repairs paid for with diocesan money, and assigned a priest to serve the community. In 1868 the
Diocese of Tucson was established. It provided for regular services to be held again at the church. In 1872, the
Sisters of St. Joseph of Carondelet opened a school at the mission for the Tohono O'odham children. In 1895, a grant of $1,000 was given to repair the building. More classrooms were added in 1900. The Franciscans returned to the mission in 1913. In 1947, they built a new school next to the church for the local children. == Missionaries ==