Based upon what you have read has the immigration caused large amounts of unemployment within the united states in the last twenty years

I would say No, but this is arguable

Explanation:

Immigration fills those jobs that people essentially do not want such as a electrician or even janitorial services. I'm unsure what you were reading before this, but the unemployment rates have gone down when immigration is at a high.

the exclusive possession or control of the supply or trade in a commodity or service.