American servicemen harassed the Mexican American soldiers for their "barrio English", Mexican American soldiers proved decisive in several key skirmishes, including the Battle of Saint-Mihiel and the Meuse–Argonne offensive. David B. Barkley, one Mexican American man from Laredo, was posthumously awarded the Medal of Honor for scouting behind enemy lines in France. And Marcelino Serna, who immigrated to the United States from Mexico as a young man, was awarded the Distinguished Service Cross. During the war, Serna singlehandedly destroyed a German machine gun site in one battle. Two weeks later, he took out 26 enemy soldiers, captured 26 more as prisoners, and successfully prevented his fellow American soldiers from executing the captured men. Serna returned to the United States as the most decorated soldier from the state of Texas. 1920s Rise of the KKK In the years after World War I, the rising tide of nativism continued to grow in the 1920s. The Second Ku Klux Klan was a new organization patterned after the original KKK of the 1860s. It was anti-Catholic and anti-immigrant and taught that all Mexicans and Mexican Americans were "subhuman foreigners". The KKK mounted an extensive campaign of violence across the Southwest. The KKK had a strong presence in Texas and California. The organization had adherents in rural communities in both states, and held major political control in large cities. In Dallas, where the KKK gained control over the city's politics, it sought to completely close off the border with Mexico. In San Diego, the KKK was led by many of the city's elite. According to Ernesto Galarza, a labor activist and professor, "Mexicans were seen as an endangerment to traditional American values. [Even the clergy] often ignored the Klan's abuses toward Latinos". The KKK in Southern California regularly lynched, tortured, dragged, and murdered Mexicans and Mexican Americans. Mercedes Acasan Garcia, a refugee of the Revolution working as a maid in San Diego in the 1920s, stated, "Since they were ragged Wetbacks, nobody cared who they were and nothing was done about it." The KKK was also extremely politically powerful in Los Angeles, and in 1928, the KKK senior member John Clinton Porter was elected mayor of the city. Colorado was another area with extensive Klan activity. During World War I, Colorado companies sought to fill labor gaps left by soldiers through recruiting refugees of the Mexican Revolution (who had arrived in the United States in