N0mesorah,
The main reason why the immigration laws of 100-200 years ago aren�t feasible is because back then once you came into the country you were on your own. If you didn�t have money for healthcare for example, then you died. It was that simple.
Nowadays it would cost tens of thousands of dollars to support a single immigrant until they found a well paying job, America can�t afford to take in millions of people a year.
I personally feel that the correct strategy would be to teach immigrants English when they come in, have live in schools to bring them up to a full high school education, and then help them with job placement. In order for this to work, I believe in a policy forcing every company which sells goods in the USA to produce 50% of their goods in America. The government can even subsidize the added cost up to the amount of tax money generated from the new jobs. This I believe should result in a healthy job market.
