“Mexico is moving north. Ethnically, linguistically and culturally, the verdict of 1848 is being over-turned. Will this Mexican nation within a nation advance the goals of the Constitution — to “insure domestic tranquility” and ‘make us a more perfect union’? Or have we imperiled our union?”

17 U.S. (4 Wheaton) 316, 404-405
McCulloch v. Maryland (1819)
Context: The convention which framed the Constitution was indeed elected by the State legislatures. But the instrument, when it came from their hands, was a mere proposal, without obligation or pretensions to it. It was reported to the then existing Congress of the United States with a request that it might "be submitted to a convention of delegates, chosen in each State by the people thereof, under the recommendation of its legislature, for their assent and ratification." This mode of proceeding was adopted, and by the convention, by Congress, and by the State legislatures, the instrument was submitted to the people. They acted upon it in the only manner in which they can act safely, effectively and wisely, on such a subject — by assembling in convention. It is true, they assembled in their several States — and where else should they have assembled? No political dreamer was ever wild enough to think of breaking down the lines which separate the States, and of compounding the American people into one common mass. Of consequence, when they act, they act in their States. But the measures they adopt do not, on that account, cease to be the measures of the people themselves, or become the measures of the State governments. From these conventions the Constitution derives its whole authority. The government proceeds directly from the people; is "ordained and established" in the name of the people, and is declared to be ordained, "in order to form a more perfect union, establish justice, insure domestic tranquillity, and secure the blessings of liberty to themselves and to their posterity." The assent of the States in their sovereign capacity is implied in calling a convention, and thus submitting that instrument to the people. But the people were at perfect liberty to accept or reject it, and their act was final. It required not the affirmance, and could not be negatived, by the State Governments. The Constitution, when thus adopted, was of complete obligation, and bound the State sovereignties.

As quoted in "Preparing to Meet Trump, Mexican Leader Seeks Common Ground" http://archive.is/PYJeS#selection-2131.1-2131.206 (23 January 2017), by Azam Ahmed, The New York Times

Interview with the Washington, D.C. Evening Star (12 March 1889)
1890s

TV Special for Iowa, December 2007 http://www.youtube.com/watch?v=uQNWHmiGj-k
2000s, 2006-2009

2000s, State of Emergency (2006)

Vision for Scotland in the European Union (December 12, 2007)

On the Irrepressible Conflict (1858)
Context: The Union is a confederation of States. But in another aspect the United States constitute only one nation. Increase of population, which is filling the States out to their very borders, together with a new and extended network of railroads and other avenues, and an internal commerce which daily becomes more intimate, is rapidly bringing the States into a higher and more perfect social unity or consolidation. Thus, these antagonistic systems are continually coming into closer contact, and collision results.
Shall I tell you what this collision means? They who think that it is accidental, unnecessary, the work of interested or fanatical agitators, and therefore ephemeral, mistake the case altogether. It is an irrepressible conflict between opposing and enduring forces, and it means that the United States must and will, sooner or later, become either entirely a slaveholding nation, or entirely a free-labor nation.

1860s, First State of the Union address (1861)

Address By Dr. Shanker Dayal Sharma President Of India On The Occasion Of The 50th Anniversary Of The First Sitting Of The Constituent Assembly