“If we would reach a degree of civilization higher and grander than any yet attained, we should welcome to our ample continent all the nations, kindreds, tongues and peoples, and as fast as they learn our language and comprehend the duties of citizenship, we should incorporate them into the American body politic. The outspread wings of the American eagle are broad enough to shelter all who are likely to come. As a matter of selfish policy, leaving right and humanity out of the question, we cannot wisely pursue any other course. Other governments mainly depend for security upon the sword; ours depends mainly upon the friendship of the people. In all matters, in time of peace, in time of war, and at all times, it makes its appeal to the people, and to all classes of the people. Its strength lies in their friendship and cheerful support in every time of need, and that policy is a mad one which would reduce the number of its friends by excluding those who would come, or by alienating those who are already here.”

1910s, The New Nationalism (1910)
Context: I do not ask for overcentralization; but I do ask that we work in a spirit of broad and far-reaching nationalism when we work for what concerns our people as a whole. We are all Americans. Our common interests are as broad as the continent. I speak to you here in Kansas exactly as I would speak in New York or Georgia, for the most vital problems are those which affect us all alike. The national government belongs to the whole American people, and where the whole American people are interested, that interest can be guarded effectively only by the national government. The betterment which we seek must be accomplished, I believe, mainly through the national government.

2014, Address to the Nation on Immigration (November 2014)

1940s, State of the Union Address — The Four Freedoms (1941)

1910s, Letter to the American Defense Society (1919)
Context: 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 man's becoming in very fact an American, and nothing but an American. If he tries to keep segregated with men of his own origin and separated from the rest of America, then he isn't doing his part as 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, and this excludes the red flag, which symbolizes all wars against liberty and civilization, just as much as it excludes any foreign flag of a nation to which we are hostile. We have room for but one language here, and that is the English language, for we intend to see that the crucible turns our people out as Americans, of American nationality, and not as dwellers in a polyglot boarding-house; and we have room for but one soul loyalty, and that is loyalty to the American people.

Nobel Peace Prize Winner Speech (October 10, 2014)

The Crisis No. XIII
1770s, The American Crisis (1776–1783)

Speech on the floor of the US Senate (3 April 2006). "Obama Fence Statement" https://www.c-span.org/video/?c4652652/obama-fence-statement, starting at about 2:05.
2006

Declaration of Sentiments, Boston Peace Conference http://fair-use.org/the-liberator/1838/09/28/declaration-of-sentiments-adopted-by-the-peace-convention#p3 (28 September 1838)

Lews Therin Telamon
(15 October 1993)