What impact did the new immigration of the 1840s and 1850s have on american cities?

The new immigration of the 1840s and 1850s impacted the United States in times of economic stress and foreigners played a part in this impact. Mainly the immigrants were the Chinese and at that time the phenomenon is known as "The Gold Rush in California" was unleashed. The Chinese worked in the mines, in the agricultural sector, in factories, restaurants, laundries. And the social and cultural impact affected the foreign nations and the United States in several aspects that gave rise to the history of American civilization.