The mural consisted of 27 panels and covered of wall space . The mural panels depicted various historical events from California 's past . It included the 1877 anti-Chinese Sand Lot riots , the 1934 San Francisco Waterfront Strike , and the Trial of trade unionist Tom Mooney , that was based on fabricated evidence . Refregier used these tragedies as inspiration . Refregier " believed that art must address itself to contemporary issues and that a mural painting in particular must not be ' banal , decorative embellishment , ' but a ' meaningful , significant , powerful plastic statement based on the history and lives of the people . ' " The mural also depicted : the California Gold Rush ; the 1860s building by Union Pacific of the western First Transcontinental Railroad ; the disastrous 1906 San Francisco earthquake and fire ; and further into the twentieth century with the city 's Second World War contributions , and culminating in the 1945 signing of the United Nations Charter in the San Francisco War Memorial Opera House . Some were suspicious of Refregier as a communist because of his Russian — USSR background , and his mural topics about social issues . None of this bothered Refregier , he was only concerned about his art
1906 San Francisco earthquake
1906 San Francisco earthquake
Anton Refregier