of them went home by 1870 when the railroad was finished. Those who stayed on worked in mining, agriculture, and opened small shops such as groceries, laundries, and restaurants. Hostility against the Chinese remained high in the western states/territories as seen by the Chinese Massacre Cove episode and the Rock Springs massacre. The Chinese were generally forced into self-sufficient "Chinatowns" in cities such as San Francisco, Portland, Seattle, and Los Angeles. In Los Angeles, the last major anti-Chinese riot took place in 1871, after which local law enforcement grew stronger. In the late 19th century, Chinatowns were squalid slums known for their vice, prostitution, drugs, and violent battles between "tongs". By the 1930s, however, Chinatowns had become clean, safe and attractive tourist destinations. The first Japanese arrived in the U.S. in 1869, with the arrival of 22 people from samurai families, settling in Placer County, California, to establish the Wakamatsu Tea and Silk Farm Colony. Japanese were recruited to work on plantations in Hawaii, beginning in 1885. By the late 19th Century, more Japanese emigrated to Hawaii and the American mainland. The Issei, or first-generation Japanese immigrants, were not allowed to become U.S. citizens because they were not "a free white person", per the United States Naturalization Law of 1790. This did not change until the passage of the Immigration and Nationality Act of 1952, known as the McCarran-Walter Act, which allowed Japanese immigrants to become naturalized U.S. citizens. By 1920, Japanese American farmers produced US$67 million worth of crops, more than ten percent of California's total crop value. There were 111,000 Japanese Americans in the U.S., of which 82,000 were immigrants and 29,000 were U.S. born. Congress passed the Immigration Act of 1924 effectively ending all Japanese immigration to the U.S. The U.S.-born children of the Issei were citizens, in accordance to the 14th Amendment to the United States Constitution. Hispanics The great majority of Hispanics who had been living in the former territories of New Spain remained and became American citizens in 1848. The 10,000 or so Californios also became U.S. citizens. They lived in southern California and after 1880 were overshadowed by the hundreds of thousands of new arrivals from the eastern states. Those in New Mexico dominated towns and villages that changed little until well into the 20th century. New arrivals from Mexico arrived, especially after the Revolution of 1911 terrorized thousands of villages all across