What laws were made that stopped immigrants from taking over AmericaI'm in US History, so this would be

What laws were made that stopped immigrants from taking over America

I'm in US History, so this would be

about the past. I don't recall when exactly, but it's in history class, so I'd assume either 19th or 20th century, back when they worked in dirty and dangerous environments, low wages, but later than that, when they allowed it more, but then they started taking jobs and stuff.