Teddy Roosevelt had some interesting thoughts on American immigration.

On allegiance to America, he spoke against a “50/50 allegiance,” and said:

In the first place, we should insist that if the immigrant who comes here in good faith becomes an American and assimilates himself to us, he shall be treated on an exact equality with everyone else, for it is an outrage to discriminate against any such man because of creed, or birthplace, or origin. But this is predicated upon the person’s becoming in every facet an American, and nothing but an American…There can be no divided allegiance here. Any man who says he is an American, but something else also, isn’t an American at all. We have room for but one flag, the American flag… We have room for but one language here, and that is the English language… and we have room for but one sole loyalty and that is a loyalty to the American people. (Roosevelt, 1907)

also:

It is our boast that we admit the immigrant to full fellowship and equality with the native-born. In return we demand that he shall share our undivided allegiance to the one flag which floats over all of us. (Roosevelt, 1917)

on English as a primary language:

Let us say to the immigrant not that we hope he will learn English, but that he has got to learn it. Let the immigrant who does not learn it go back. He has got to consider the interest of the United States or he should not stay here. He must be made to see that his opportunities in this country depend upon his knowing English and observing American standards. (Roosevelt, 1916)

and:

Every immigrant who comes here should be required within five years to learn English or to leave the country…English should be the only language taught or used in the public schools.” (Roosevelt, 1918)

Also see: Snopes and Urban Legends.