Many also worked as agricultural laborers in farming valleys in the border states, such as Tucson in Arizona, the Rio Grande Valley in Texas, and most especially, the Imperial Valley in California. Anglo-Americans hired Mexicans and Mexican Americans to work in the region's year-round agricultural economy. Mexican farm laborers, along with African Americans, Filipino Americans, Japanese-Americans, and even Armenian Americans, Punjabi Americans, Native Hawaiians and Native Americans, were instrumental in California becoming the nation's top agricultural state. In this shift toward agricultural dominance, California relied on the cheap labor of Mexicans and Mexican Americans in a wide variety of fields. By the mid-1920s, California cotton farms were around five times larger than farms in the Deep South. This meant they needed large numbers of manual laborers, as well as technicians, since California farmers adopted tractors and picking machines at rates faster than any other region. The ability of Mexican laborers to adapt to industrial farming was crucial to the state's success. Nevertheless, even as labor unions in the 1920s grew rapidly to protect workers, some mainstream organizations, such as the AFL, were blatantly anti-Mexican. When Mexicans sought better working conditions, they often faced outright violence.