The earliest European settlers in the territory that would become California were Spaniards who had been granted land holdings by the King of Spain. Their descendents, known as Californios, settled in part in the area that became Orange County, many of them marrying local Native Americans and Mexicans during the era when Mexico controlled the territory.

The 1890 U.S. census listed only 162 Chinese and no Japanese in the area. UCI sociologist John M. Liu has noted that this "definitely undercounts the true number of Chinese," given the migratory nature of these workers at the time. During the 1880s, "farmers from Tustin regularly went to Los Angeles to hire Chinese, who stayed just for three or four months of the year" while other Chinese were more long-term. The Irvine Ranch, Liu notes, "employed between 40-50 ‘Celestials' prior to 1887" (China was then termed the "Celestial Kingdom")[vi].

Two decades later, the 1910 U.S. census showed 641 Japanese and 83 Chinese in Orange County. This pattern of Japanese outnumbering Chinese continued until the 1980 U.S. census, when 21,841 Japanese were counted but only 14,575 Chinese. The 1960 U.S. census counted 747 Filipinos, along with 444 Chinese and 3,890 Japanese. The Mexican-origin population also multiplied, especially in Santa Ana, where a second-generation newspaper, The Latin American, written primarily in English, reported on civil rights issues (Item 10). After the fall of Saigon in 1975, Orange County quickly became the center of the global Vietnamese diaspora; our county is now home to more Vietnamese than anywhere else outside Vietnam.

Today immigrants total about 915,000, almost a third of Orange County's population of three million. Their diversity spans many nationalities, including Iranians, Armenians, Koreans, Mexicans, Puerto Ricans, Cubans, Dominicans, Filipinos, Cambodians, Laotians, Hmong, Bangladeshi, Asian Indians, Indonesians, Sri Lankans, Thai, Japanese, Chinese, and Vietnamese, including many people of mixed heritage. "Whites" are now a minority (Item 16).