This study uncovers the roots of racism in the Southwest during the first half of the twentieth century and explores how racism affected people of color. It does so by examining connections between racism during the twentieth century and the historical and ideological legacy of Westward expansion. Frontier mores, such as violence, individualism, masculinity, and landownership, that justified Indian removal in the United States during the nineteenth century continued to inform racial prejudice in the Southwest well into the twentieth century. In the context of racial prejudice, this dissertation examines the experiences of people of color who lived, worked, and farmed in Imperial Valley, California. It delves into the complexities of race relations and racial prejudices within a multiplicity of racial groups in the Valley.

In doing so, this study goes beyond the Black-white and Mexican-white binaries and investigates racism in the context of a pattern of ethnic and racial succession that included Yuma Indians, Japanese, Punjabis, Mexicans, Filipinos, and white Dust Bowl migrants. Within this multiethnic approach, it emphasizes the contributions of Yuma Indians during the beginnings of industrialized agriculture in the Valley and examines their experiences alongside those of Mexicans and whites. Moreover, this dissertation develops a new perspective on race relations by addressing the conflicts people of color experiences within their own ethnic and/or racial group, in particular, the turmoil that existed within the Japanese and Punjabi communities. They confronted racial prejudice in the larger white community while grappling with dysfunction within their respective racial and/or ethnic group.

This study probes the strikes that swept the Valley during the Great Depression and asks how the values which emerged during the expansion of the West informed the violent practices and rhetoric large growers employed. Finally, this work addresses how frontierism promoted white supremacy during World War II as white citizens blamed interethnic violence, racial tensions, and poor moral values on the proximity of the U.S.-Mexico border. The border took on a deeply racialized meaning in the Valley as whites upheld the hierarchal and unequal power dynamic which harkened back to the arrival of the first colonists.