“It is one of the strange ironies of history, that in a nation founded on the principle that all men are created equal, men are still arguing over whether the color of a man’s skin determines the content of his character.”

Source: Father and Child Reunion (2001), p. 167.

Variant: I have a dream that my four little children will one day live in a nation where they will not be judged by the color of their skin but by the content of their character.

1960s, The Rising Tide of Racial Consciousnes (1960)

2000s, Is Diversity Good? (2003)
Context: To allow slavery to be introduced into free territories, where it had not hitherto existed, was, Abraham Lincoln held, a very bad thing. His opponent, Stephen A. Douglas, held that it was a sacred right, belonging to the people of each territory, to decide for themselves whether or not to have slavery among their domestic institutions. According to Douglas, Lincoln wanted to destroy the diversity upon which the union had subsisted, by insisting that all the states ought to be free. But for Douglas himself, the principle of 'popular sovereignty' did not admit of exceptions. There was to be no diversity, no deviation from the right of the people to decide. For Lincoln the wrongness of slavery meant that no one, and no people, had the right to decide in its favor. For Lincoln, the principle of human equality, "that all men are created equal", did not admit exceptions.

radio address https://georgewbush-whitehouse.archives.gov/news/releases/2008/11/20081101.html (1 November 2008) <br class="br">2000s, 2008

Letter http://www.trsite.org/content/pages/speaking-loudly (1 September 1903), Oyster Bay, New York <br class="br">1900s

1960s, The American Promise (1965)
Context: This was the first nation in the history of the world to be founded with a purpose. The great phrases of that purpose still sound in every American heart, North and South: "All men are created equal" — "government by consent of the governed" — "give me liberty or give me death." Well, those are not just clever words, or those are not just empty theories. In their name Americans have fought and died for two centuries, and tonight around the world they stand there as guardians of our liberty, risking their lives. Those words are a promise to every citizen that he shall share in the dignity of man. This dignity cannot be found in a man's possessions; it cannot be found in his power, or in his position. It really rests on his right to be treated as a man equal in opportunity to all others. It says that he shall share in freedom, he shall choose his leaders, educate his children, and provide for his family according to his ability and his merits as a human being.

As quoted in Pitchfork Ben Tillman, South Carolinian (1967), by Francis Butler Simkins. Louisiana State University Press. OCLC 1877696, p. 144.

1960s, Civil Rights Bill signing speech (1964)