Coinciding with droughts, floods, and violent political rebellions in mainland China, the Gold Rush and corresponding economic boom in California drew many Chinese (mostly men) across the Pacific Ocean. The crossing was exceptionally unpleasant, lasting 62 days on average, with miserable conditions that modern scholars have compared to African slave ships. By the end of 1851, there were an estimated 4,000 Chinese nationals in California; by the end of 1852, just one year later, there were approximately 25,000. Before 1860, only 8% of the Chinese population stayed in San Francisco, while the vast majority sought their fortunes in the gold fields.

The early Chinese miners faced increasing discrimination and hostility from their white counterparts. Initially, when the number of Chinese miners was relatively small, they attracted little attention, and were mostly seen as picturesque and amusing. As their numbers grew, their presence excited increased violence, hostility, and envy. Before 1852, there was not much specific anti-Chinese activity, but when Governor John Bigler declared in an 1852 speech that the Chinese were a menace to the state, anti-Chinese activity accelerated. Chinese miners, for example, were especially hard hit by the ever-increasing miner's taxes that were levied cruelly and unevenly on miners.

The Chinese in San Francisco faced a different set of circumstances than their counterparts in the mines, and they adapted to meet the economic opportunities available to them. San Francisco circa 1850 had an overwhelmingly male population, and consequently laundry and other household tasks presented often insurmountable challenges to the otherwise-occupied men. The Chinese in San Francisco, many of whom had been forced from the mines, started laundries in great number; these required a low capital investment, little space, and allowed the Chinese to avoid working for or competing with whites for jobs. Chinese restaurants also flourished, though in less numbers than the laundries due to their greater initial expense. The Chinese also engaged heavily in the fishing industry, but even there they could not escape the increasingly harsh taxes and fines that were levied against them. The Chinese also worked as farmers, domestic helpers, and in trade industries making boots, candles, cigars, and other products.