Final answer:
The official U.S. immigration policy during the 1800s was tightly regulated, with laws and policies limiting and controlling immigration.
Step-by-step explanation:
The term that best describes official U.S. immigration policy during the 1800s is Tightly regulated.
During this time, the government implemented various laws and policies to control and limit immigration. The most significant of these was the Chinese Exclusion Act of 1882, which prohibited Chinese laborers from entering the country. Other laws, like the Immigration Act of 1864 and the Immigration Act of 1875, imposed restrictions and conditions on specific groups of immigrants.
These policies were driven by concerns over economic competition, cultural differences, and a desire to maintain a certain demographic makeup of the population.
Learn more about U.S. immigration policy in the 1800s