Final answer:
About 300,000 Chinese immigrants arrived on the West Coast between 1851-1882, contributing to development but facing discrimination, leading to the Chinese Exclusion Act of 1882.
Step-by-step explanation:
Between 1851-1882, about 300,000 Chinese arrived on the West Coast seeking opportunities during events such as the Gold Rush and the construction of the Transcontinental Railroad. The massive inflow of Chinese laborers, willing to work for low wages, contributed significantly to the regional development but also led to severe racial tensions and discrimination. This period of immigration ended with the implementation of the Chinese Exclusion Act of 1882, which severely restricted the entry of Chinese laborers into the United States.