from Wikipedia
Our Lady of Perpetual Help Parish was established in 1919 when Bishop Theophile Meerschaert, the first Bishop of Oklahoma City, assigned Monsignor Monnot its first pastor on January 19. Mass for the parish was initially celebrated in an automobile showroom on Classen Boulevard. The first church building was a wood structure built in May 1919 on NW 31st Street between Western and Lake. The following month the parish held a ground breaking for a combination church and school building.
Construction of the present church building was begun on July 3, 1923, and was completed in February 1924. A frame rectory was completed in July of the same year. Pope Pius XI elevated Our Lady of Perpetual Help to a cathedral in 1931, replacing St. Joseph Cathedral downtown.
Thirty Vietnamese families, refugees from the Vietnam War, joined the parish in 1975. Their numbers have continued to grow in the succeeding years.
The parish undertook a renovation project in 1993 that included a new pipe organ by W. Zimmer and Sons of Charlotte, North Carolina, a new baptistery, electrical and other additions to the parish plant.