The Azusa Street Revival was a historic Pentecostal revival that began in Los Angeles, California, in 1906 and is widely regarded as the catalyst for the modern Pentecostal movement. Led by William J. Seymour, the revival was characterized by intense worship, speaking in tongues, and an integrated congregation of people from various racial and social backgrounds. The revival, which lasted for roughly three years, spread Pentecostalism throughout the United States and the world as visitors and missionaries carried its practices and teachings to their home churches and mission fields.