The Earl Warren Showgrounds was originally developed as the permanent location for the Santa Barbara National Horse and Flower show as well to attract and support other equestrian and agricultural events to the Santa Barbara area. In 1950, a site at the corner of Las Positas Road and Calle Real was selected for the showground. The state of California, using funds provided by the horse show association, purchased 136.5 acres of land at the site. To gain support for construction of the facilities from the city of Santa Barbara and the local community, the district gave eighty-two acres to the city to add to the community golf course and ten acres for the construction of Adams Elementary School.
In 1955 the 19th Agricultural District received state authorization to plan and build the only fairgrounds in California specifically designed for horse and flower shows. The Equestrian Facility was completed in 1958, with the Exhibit building finished 1959 and the administration building was added in 1961. (earlwarren.com)