The Panama-California Exposition was an exposition held in San Diego, California

California

California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...

 between March 9, 1915 and January 1, 1917. The exposition celebrated the opening of the Panama Canal

Panama Canal

The Panama Canal is a ship canal in Panama that joins the Atlantic Ocean and the Pacific Ocean and is a key conduit for international maritime trade. Built from 1904 to 1914, the canal has seen annual traffic rise from about 1,000 ships early on to 14,702 vessels measuring a total of 309.6...

, and was meant to tout San Diego as the first U.S. port of call for ships traveling north after passing westward through the canal. The fair was held in San Diego's large urban Balboa Park.
Real estate developer "Colonel" David Collier, at the time often referred to as San Diego's greatest asset, was responsible for selecting both the location in the city park and a Pueblo Revival

Pueblo Revival Style architecture

The Pueblo Revival style is a regional architectural style of the Southwestern United States which draws its inspiration from the Pueblos and the Spanish missions in New Mexico. The style developed at the turn of the 20th century and reached its greatest popularity in the 1920s and 1930s, though it...

 and Mission Revival Style architecture

Mission Revival Style architecture

The Mission Revival Style was an architectural movement that began in the late 19th century for a colonial style's revivalism and reinterpretation, which drew inspiration from the late 18th and early 19th century Spanish missions in California....

 architectural style.