Black immigrants

1, whites are mainly Europeans such as Britain, who colonized and expanded America after the opening of the new air route (note that what was said upstairs is wrong, there are no whites in America, only indigenous Indians).

2. Blacks are Africans who were sold by European colonists to America for the later slave trade (triangle trade);

3. China people were brought to the United States by capitalist countries in the form of labor after most countries in the world entered capitalism. After the Opium War, there was a provision in the Beijing Treaty that Chinese workers were allowed to go abroad.

Impact:

1 brought a lot of labor and technology to the development of the western United States.

2. Promoted the development of American capitalism.

It played an important role in several industrial revolutions in America.

4. As a whole, it has made important contributions to the economic development of the United States and provided labor force for the United States to become an economic power.