http://en.wikipedia.org/wiki/List_of...on_legislation
We have certainly gone far off the path our founders intended when it comes to immigration.
Somehow the Union survived with a % of foreign-born residents higher than it is now.
Fun fact: before 1906, knowing english was not a requirement of citizenship. I thought that was kind of funny considering how butthurt conservatives get over the issue, one that the Founders and 5 generations after them seemed to think was not worth bothering over.
If conservatives think that they can hide from the world labor markets, they are deluding themselves. Immigration restrictions work to "help America" the same way minimum wage laws and various other regulations do; ie, they hurt America significantly. Again, that isn't economic heresy; go ask any economist of any political bent and he'll tell you.
Edit: Immigration should certainly be distinct from citizenship, as well.