Many scholars explain the institution of the Chinese exclusion law and similar laws as the product of the widespread anti-Chinese movement in California in the second half of the 19th century. The Chinese have been a significant minority on the West Coast since the mid-19th century. At first they worked in gold mines, where they showed a way to find gold. As a result, they encountered hostilities and were gradually forced to leave the field to go to urban areas such as San Francisco, where they often simply carried out some of the dirtiest and hardest jobs. Americans in the West have emphasized their stereotype of Chinese as degraded, exotic, dangerous and competing for jobs and wages. Senator John F. Miller of California, a supporter of China`s exclusionary law, argued that Chinese workers “mechanically… blunt nerves, but little influenced by heat or cold, wired, sinewy, with iron muscles. Partly in response to this stereotype, organized work in the West has made limiting the influx of Chinese into the United States one of its goals. In other words, the exclusion was the result of an anti-Chinese atmosphere at the base.
Other scientists have argued that exclusion should be attributed to top-down politics and not to an upward movement, explaining that national politicians manipulated white workers to gain electoral advantage. Still others have adopted a “national thesis of racism” centered on endemic anti-Chinese racism in early American national culture. The effects of exclusion laws went beyond restriction, marginalization and, ironically, Chinese activation. It marked the transition from a previously open immigration policy in the United States to one in which the federal government controlled immigrants. Criteria have been gradually defined so that people – in terms of ethnicity, gender and class – are admitted. Immigration patterns, immigration communities, identities and racial categories have been significantly affected. The very definition of what it means to be an American has become more marginal. In the meantime, Chinese exclusionary practices have marked immigration legislation during this period.