Dr. Emily Abel will discuss the establishment of the Los Angeles County Department of Health during 1914 as it was confronted with the overwhelming task of building a public health infrastructure for a burgeoning and diverse population. She will address how Los Angeles County Department of Health reports focused almost exclusively on the various infectious diseases associated with Mexican immigrants, and how segregation of Mexicans occurred in Los Angeles County clinics. She will share documentation of how County health officers participated in efforts to exclude Mexicans during the 1920s and expel them during the 1930s. Lastly, she will cover how both state and local health authorities joined the mid-1930s campaign to remove Filipinos from the county.