The Azusa Street Revival, the primary catalyst for the spread of Pentecostalism in the 20th century, opened in Los Angeles.

The Azusa Street Revival was a historic series of revival meetings that took place in Los Angeles, California. It was led by William J. Seymour, an African-American preacher. The revival began on April 9, 1906, and continued until roughly 1915.

Pentecostalism or classical Pentecostalism is a movement within the broader Evangelical wing of Protestant Christianity that emphasizes direct personal experience of God through baptism with the Holy Spirit. The term Pentecostal is derived from Pentecost, an event that commemorates the descent of the Holy Spirit upon the Apostles and other followers of Jesus Christ while they were in Jerusalem celebrating the Feast of Weeks, as described in the Acts of the Apostles.