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.'"