Mission La Purisima was originally established at a site known to the Chumash people as Algsacpi and to the Spanish as the plain of Rio Santa Rosa, one mile south of Lompoc. (During the mission period, the Chumash spoke the Purisimeño language.) The Viceroyalty of New Spain made an exception to the rule that no California mission was to be established within seven miles of any pueblo in Las Californias, as Lompoc was so small.
By 1803, the Mission Indians population had increased, by Indian Reductions, to 1,436 Chumash people. At the mission there were also 3,230 cattle, 5,400 sheep, 306 horses, and 39 mules. In the same year, there was a harvest of 690 fanegas of wheat, corn and beans (a fanega equaling about 220 pounds).
An earthquake on December 21, 1812, severely damaged the mission buildings. New buildings were constructed four miles east of the pueblo at their present location, which was known to the Chumash as Amúu, and to the Spanish as La Cañada de los Berros, now part of the reconstructed La Purísima Mission State Historic Park. Ruins of the original mission are at 508 South F Street, near East Locust Avenue in Lompoc, California.
After Mexico won the Mexican War of Independence in 1823, Spanish funding ceased to the Santa Barbara Presidio. Many soldiers at the mission who were no longer being paid by the new Mexican government took out their frustrations on the local Chumash Indians. After a soldier apparently beat an Indian at nearby Mission Santa Inés, the Chumash Revolt of 1824 occurred at that mission. It spread to La Purisima Mission, where the Chumash people took over the mission for one month until more soldiers arrived from Monterey Presidio. Eventually, the Chumash lost their hold on the mission with many leaving the mission soon there after. However, many of the Indians who had sought refuge in the neighboring mountains during the revolt returned to the mission.
The altar inside La Purisima Mission.
Following independent Mexico's secularization of the Alta California missions from 1834 to 1843, the buildings of La Purisima Mission were abandoned, and the lands were granted Rancho Ex-Mission la Purisima. By 1934, only nine of the buildings remained intact.
In the 20th century, the Civilian Conservation Corps (CCC) pledged to restore the mission if enough land could be provided to convert it into a historic landmark. The Catholic Church and the Union Oil Company donated sufficient land for the CCC to proceed with the restoration. The nine buildings as well as many small structures and the original water system were fully restored with the mission's dedication occurring on December 7, 1941, the same day the United States entered World War II. Today, La Purisima Mission is the only example in California of a complete mission complex.