Natalia Molina argues that public health discourse contributed to racializing Chinese, Japanese, and Mexican laborers in Los Angeles County in the late 1800s to the mid 1900s. For these groups, a multitude of urban issues, but especially inadequate access to clean water, sewage processing, garbage pickup, and health care contributed to morbidity and disproportionately high infant mortality rates. When epidemics inevitably spread, all attention was paid to immigrant spaces, effectively rendering invisible more widespread issues and laying the blame on biological or cultural factors, whichever was the more convenient explanation. Public health discourse served the dual purposes of assigning blame, binding negative associations with immigrants, and allowing public officials to extend the reach of the State well beyond the clinic door. Chinese people fought attempts to destroy their laundry and vegetable purveying industries by appealing to a Chinese business conglomerate to petition the mayor; at the same time Japanese farmers were said to be biologically predisposed to stooping, their “fecundity” was also billed as a threat. While Mexican workers were initially designated “white,” this changed as the Great Depression put pressure on the local economy. Forced deportations of Mexicans under the guise of their being a public health threat and their return in the 40s under the Bracero program highlight how public health discourse responded to economic expediency. Molina’s regional approach to racialization in public health discourse on Chinese, Japanese, and Mexican laborers illustrates how racial fault lines in late nineteenth and early twentieth century Los Angeles transcended established black-white binaries.