“Some twelve thousand voters in the heretofore slave-state of Louisiana have sworn allegiance to the Union, assumed to be the rightful political power of the State, held elections, organized a State government, adopted a free-state constitution, giving the benefit of public schools equally to black and white, and empowering the Legislature to confer the elective franchise upon the colored man. Their Legislature has already voted to ratify the constitutional amendment recently passed by Congress, abolishing slavery throughout the nation. These twelve thousand persons are thus fully committed to the Union, and to perpetual freedom in the state — committed to the very things, and nearly all the things the nation wants — and they ask the nations recognition and it's assistance to make good their committal. Now, if we reject, and spurn them, we do our utmost to disorganize and disperse them. We in effect say to the white men "You are worthless, or worse — we will neither help you, nor be helped by you." To the blacks we say "This cup of liberty which these, your old masters, hold to your lips, we will dash from you, and leave you to the chances of gathering the spilled and scattered contents in some vague and undefined when, where, and how." If this course, discouraging and paralyzing both white and black, has any tendency to bring Louisiana into proper practical relations with the Union, I have, so far, been unable to perceive it. If, on the contrary, we recognize, and sustain the new government of Louisiana the converse of all this is made true. We encourage the hearts, and nerve the arms of the twelve thousand to adhere to their work, and argue for it, and proselyte for it, and fight for it, and feed it, and grow it, and ripen it to a complete success. The colored man too, in seeing all united for him, is inspired with vigilance, and energy, and daring, to the same end. Grant that he desires the elective franchise, will he not attain it sooner by saving the already advanced steps toward it, than by running backward over them? Concede that the new government of Louisiana is only to what it should be as the egg is to the fowl, we shall sooner have the fowl by hatching the egg than by smashing it? Again, if we reject Louisiana, we also reject one vote in favor of the proposed amendment to the national Constitution. To meet this proposition, it has been argued that no more than three fourths of those States which have not attempted secession are necessary to validly ratify the amendment. I do not commit myself against this, further than to say that such a ratification would be questionable, and sure to be persistently questioned; while a ratification by three-fourths of all the States would be unquestioned and unquestionable.”

1820s, Letter to A. Coray (1823)
Context: But, whatever be the constitution, great care must be taken to provide a mode of amendment, when experience or change of circumstances shall have manifested that any part of it is unadapted to the good of the nation. In some of our States it requires a new authority from the whole people, acting by their representatives, chosen for this express purpose, and assembled in convention. This is found ' too difficult for remedying the imperfections which experience develops from time to time in an organization of the first impression. A greater facility of amendment is certainly requisite to maintain it in a course of action accommodated to the times and changes through which we are ever passing. In England the constitution may be altered by a single act of the legislature, which amounts to the having no constitution at all. In some of our States, an act passed by two different legislatures, chosen by the people, at different and successive elections, is sufficient to make a change in the constitution. As this mode may be rendered more or less easy, by requiring the approbation of fewer or more successive legislatures, according to the degree of difficulty thought sufficient, and yet safe, it is evidently the best principle which can be adopted for constitutional amendments.

Striking down the "Take-Title" provision of the Low-Level Radioactive Waste Policy Amendments Act in New York v. United States, 505 U.S. 144 (1992).

1960s, Special message to Congress on the right to vote (1965)

1870s, Seventh State of the Union Address (1875)
Context: As the primary step, therefore, to our advancement in all that has marked our progress in the past century, I suggest for your earnest consideration, and most earnestly recommend it, that a constitutional amendment be submitted to the legislatures of the several States for ratification, making it the duty of each of the several States to establish and forever maintain free public schools adequate to the education of all the children in the rudimentary branches within their respective limits, irrespective of sex, color, birthplace, or religions; forbidding the teaching in said schools of religious, atheistic, or pagan tenets; and prohibiting the granting of any school funds or school taxes, or any part thereof, either by legislative, municipal, or other authority, for the benefit or in aid, directly or indirectly, of any religious sect or denomination, or in aid or for the benefit of any other object of any nature or kind whatever.

2000s, The Real Abraham Lincoln: A Debate (2002), The Right of Secession Is Not the Right of Revolution

Remarks on the Republican platform (1860)

2000s, The Real Abraham Lincoln: A Debate (2002), Q&A

2010s, Interview with Sara Gabbard (2018)

Describing the people who participated in the Freedom Rides to end segregation in Albany, Georgia. in You Can't Be Neutral on A Moving Train http://www.zmag.org/zmag/articles/oldzinn.htm (1994) Ch. 4: "My Name is Freedom": Albany, Georgia