The earliest record of an Indian-born immigrant to become a naturalized U.S. citizen was Eduljee Sorabjee, who obtained U.S. citizenship in 1890. Sorabjee was ethnically Parsi*, born in Bombay (now Mumbai) in 1849. As a young man, he went to live in England for almost a decade to learn the business of cotton spinning. There he married an English wife, Louisa, and had two infant children (a daughter and son), but tragically lost his entire family to death. In 1884, he again married an English wife, Mary, and, in 1885, following his physician's advice, decided to immigrate to a warmer climate in the United States. The couple, then with a new infant daughter, arrived in New York in 1885, where they only briefly stayed. By the end of the year, they were in Los Angeles. In Los Angeles, Sorabjee found himself to be the only resident from South Asia. He and his English wife, however, were able to make important connections with other successful English expatriates living there. Sorabjee himself entered real estate investing and found a home for his family in the Lincoln Park area of Los Angeles.
Simply being an exotic South Asian wasn't all that brought Sorabjee attention. Perhaps to enhance his image in the eyes of his community, Sorabjee claimed to be a descendant of the ancient kings of Persia – Cyrus, Darius, Artexerxes, and Cambyses. He recounted how the Parsi people were forced to flee religious persecution in Persia centuries before, and how they migrated to India, achieving high-caste status in the Bombay area (now Mumbai). His tales were accepted to the point where newspaper obituaries after his death repeated them. This may have helped smooth his path to naturalization as a U.S. citizen in 1890. In all but very rare cases, Asian immigrants in the U.S. were not even allowed to begin applying for naturalization until 1943. Sorabjee managed to bypass this racial barrier to become one of the earliest South Asian immigrants to attain U.S. citizenship.
In 1893, Sorabjee and his wife Mary divorced.
By 1898, real estate had been in a downturn and Sorabjee turned his attention to water utilities. Upon taking over management of Marengo Water Works in South Pasadena, he moved to that community, where his home (reported at the historic Adobe Flores on Foothill Street) became known as "Bombay Place."
In 1910, Sorabjee was called to jury service in Los Angeles to hear a homicide case against a Latino defendant. During the process of jury selection, the prosecutor was unconvinced that Sorabjee wasn't, in fact, Latino. He questioned Sorabjee about his ability to speak Spanish and his ethnic heritage. Sorabjee restated his story of being of Persian royal descent, being of high-caste status in India, speaking five Asian languages, and having lived in England. This failed to sway the prosecutor and Sorabjee was subsequently dismissed from the jury panel. The Los Angeles Herald, writing about this occurrence, headlined its story "Royal Blood, But Not Fit for Jury Service" (May 24, 1910).
Circa 1911, Sorabjee reportedly dove into the water at one of Marengo Water Works' reservoirs in order to save a suicidal woman. Although she was saved, Sorabjee had already been suffering health problems and, after the incident, ended up with a case of tuberculosis. That and other inflictions caused his health to deteriorate over the next few years.
Sorabjee died in Long Beach on July 13, 1913, after spending a few weeks there at a property he owned. Per his wishes, his ashes, along with those of his first infant daughter who had died many years before, were scattered off Long Beach in the Pacific Ocean.
* Parsis, which means "Persians," are descendants of the Persian followers of Zoroaster who emigrated to India from Persia to escape religious persecution.
See "The Curious Case of the ‘First’ Indian-American Citizen" by Anu Kumar.