The Barnum Hall Theatre was built in 1938 by the Federal Works Project Administration (WPA) and also served as the Santa Monica Civic Auditorium when it was first built. It was designed to be a cultural center to the Santa Monica community, hosting concerts, plays, musicals, even opera, ballet and guest solo artists. For many years it did just that, enhancing Santa Monica's reputation as a fine arts community.

Barnum Hall was designed by the architectural firm of Marsh, Smith & Powell. Norman Marsh is best known for designing the many Sculptures, Plaques, Reliefs, Murals, and Fountains at USC during the mid 1970's, several buildings on the UCLA campus in the mid 1950's and the founding buildings in Venice, California in 1904.

One of Barnum Hall's designers, Henry Alfred Buxton also worked on the design of (at the time) the Grauman's Chinese Theatre, now Mann's Chinese Theatre. Barnum Hall's design went way beyond those of a traditional high school theatre. Eminent Santa Monica artist, Stanton MacDonald-Wright directed leading WPA artisans to create such works as the Viking mural on the fire curtain and the mosaic in the lobby. Additionally on the front fa?ade of the hall is a concrete bas-relief of a comedy-tragedy mask and musical instruments portrayed in the art deco style that was preeminent for many public buildings in the 1930's.

As a fine example of Streamline-Art Deco design, the structure has aesthetic value that contributes to the overall high school campus, anchoring the school with a historic reference to its earlier stages of development. The primary (east) elevation including the multi-door theatre entrance and a large multi-paned glazed grid has special artistic value due to an Art Deco motif that is incorporated into the concrete bas-relief centrally located over the large grid window. Emphasizing the geometric form, the bas-relief depicts the Greek tragedy and comedy masks and stylized musical instruments. Furthermore, interior public areas of the building contain two pieces of artwork, a fire curtain mural and a large mosaic piece, that are aesthetically and artistically significant. The fire curtain mural is entitled "Entrance of the Gods into Valhalla." The mosaic piece is called "Landing of the Vikings in Vinland." Both pieces are the work of internationally recognized artist Stanton MacDonald-Wright and were funded and completed as part of the WPA relief program.

Santa Monica excitedly embraced the building by funding two separate bond issues to complete the theatre.