To punish colonists for Boston tea party
In the beginning they had the strongest military to start with. Then they had won in Paris and took over it.
I’m not sure, but this should help you a little bit.
“The Immigration and Nationality Services of Act of 1965 was a turning point in United States policy regarding immigration. While changing previous legislation that functioned on a rigid quota system, the Act of 1965 gave preference to refugees and families, removed quotas from countries in the Western Hemisphere, and based entry to the United States on levels of skill. In forty years since, the foreign-born population of the United States has tripled in number, now prompting new legislative debate.”