The first Roman Catholics in California were Spanish friars, who established 21 Franciscan missions from San Diego to Sonoma between 1769 and 1823. After an independent Mexican government began to secularize the missions in 1833, the Indian population at the missions declined from about 25,000 to only about 7,000 in 1840. With the American acquisition of California in 1848, the Catholic Church was reorganized to include the archdiocese of San Francisco.
Protestant ministers accompanied migrant miners during the gold rush, founding 32 churches in San Francisco by 1855. These early Protestants included Baptists, Congregationalists, Methodists, Presbyterians, and Episcopalians; a group of Mormons had arrived by ship via Cape Horn in 1846. The Midwesterners who began arriving in large numbers in the 1880s were mostly Protestants who settled in southern California. By 1900, the number of known Christians in the state totaled 674,000, out of a population of nearly 1,500,000.
Small Jewish communities were established throughout California by 1861 and, in 1880, the Jewish population was estimated at 18,580.
The mainstream religions did not satisfy everybody's needs, however, and in the early 20th century, many dissident sects sprang up, including such organizations as Firebrands for Jesus, the Psychosomatic Institute, the Mystical Order of Melchizedek, the Infinite Science Church, and Nothing Impossible, among many others.
Perhaps the best-known founder of a new religion was Canadian-born Aimee Semple McPherson, who preached her Foursquare Gospel during the 1920s at the Angelus Temple in Los Angeles, won a large radio audience and thousands of converts, and established 240 branches of her church throughout the state before her death in 1944. She was typical of the many charismatic preachers of new doctrines who gave—and still give—California its exotic religious flavor. Since World War II, religions such as Zen Buddhism and Scientology have won enthusiastic followings, along with various cults devoted to self-discovery and self-actualization.
Nevertheless, the large majority of religious adherents in California continue to follow traditional faiths. In 2000, there were 10,079,310 Roman Catholics in 1,315 congregations. The next largest religion is Judaism with 994,000 adherents in 425 congregations. The Latter-day Saints follow with 529,575 adherents in 1,316 congregations. The largest Protestant churches include Southern Baptist, 471,119; Assembly of God, 310,522; Presbyterian Church USA, 229,918; and the United Methodist Church, 228,844. In 2000, there were 489 Buddhist, 131, Hindu, and 163 Muslim congregations in the state. About 53.9% of the population were not counted as members of any religious organization.
The Church of Scientology in Los Angeles, established in 1954 by the religions founder L. Ron Hubbard, is religions largest facility and also serves as a training center for leaders. The Crystal Cathedral opened in 1980 in Garden Grove, California, is the home base for the international Crystal Cathedral Ministries and the internationally televised Hour of Power. Dr. Robert H. Schuller, a minister of the Reformed Church in America presides over a congregation of over 10,000 members.