Job Recruitment Website - Immigration policy - American immigrants built them. This refers to moving in or out of the United States.

American immigrants built them. This refers to moving in or out of the United States.

Immigration here refers to immigrants, no matter in which country, it refers to foreign immigrants, so the last word is only Americans, so it refers to American immigrants, that is to say, in other countries. If you were in the United States, you would say China immigrants, or Japanese immigrants, China immigrants, and Japanese immigrants.