The Golden Gate International Exposition (GGIE) (1939 and 1940), held at San Francisco's Treasure Island, was a World's Fair celebrating, among other things, the city's two newly built bridges. The San Francisco–Oakland Bay Bridge opened in 1936 and the Golden Gate Bridge in 1937. The exposition opened from February 18, 1939, through October 29, 1939, and from May 25, 1940, through September 29, 1940.
The theme of the exposition was "Pageant of the Pacific", as it showcased the goods of nations bordering the Pacific Ocean. The theme was physically symbolized by "The Tower of the Sun", by an 80-foot statue of Pacifica, goddess of the Pacific ocean.
Timothy Ludwig Pflueger (September 26, 1892 – November 20, 1946) was a prominent architect, interior designer and architectural lighting designer in the San Francisco Bay Area in the first half of the 20th century. Together with James R. Miller, Pflueger designed some of the leading skyscrapers and movie theaters in San Francisco in the 1920s, and his works featured art by his personal friend Ralph Stackpole and challenging new artists such as Diego Rivera.
Timothy L. Pflueger, was also a member of the GGIE design committee, and came up with a plan to have an exhibition of artists on display. He contacted a wide array of artists to show their talents to the public while working within the "Fine Arts Palace", a concrete and steel industrial building measuring 335 by 78 feet intended to be an aircraft hangar after the Exposition closed. For the second time, Pflueger brought Rivera to San Francisco to paint a mural, this time as the main attraction at Art in Action.
Alfred Frankenstein of the New York Times reported from the opening day and wrote "Here the visitor is privileged to observe a kind of twenty-ring circus of art... On the floor, in a series of little ateliers, sculptors, painters, lithographers, etchers, ceramicists, weavers and whatnot are at work under the direct observation of the public." On July 29, 1940, LIFE magazine ran a story about Art in Action using a spread of color photos.
Along one wall, Rivera painted the mural Pan American Unity on ten steel-framed panels spanning 74 feet in width and reaching 22 feet in height, weighing a total of 23 tons.
Some 68 artists had participated by the end of September when the Exposition was closed. Rivera was not finished, however; he and two assistants labored for two more months in the empty exhibit hall. On Friday, November 30 and Sunday, December 2, 30,000–35,000 visitors came to Treasure Island to view the completed mural. During the painting of the mural, Frida Kahlo had arrived in San Francisco and on December 8, 1940, Rivera's 54th birthday, Kahlo and Rivera were married for the second time in a civil ceremony at San Francisco City Hall.