But like Andrew Jackson before him, Lincoln had come to understand liberty as inextricable from Union. While Jackson faced down Southern secessionist threats that foreshadowed the Civil War, Daniel Webster made an earlier rhetorical case for Union in a speech that prefigured Lincoln's.
"I have not allowed myself, sir, to look beyond the Union, to see what might lie hidden in the dark recess behind," the Massachusetts senator said in a famous debate with South Carolina's Robert Y. Hayne. "I have not coolly weighed the chances of preserving liberty when the bonds that unite us together shall be broken asunder." The notion of "Liberty first and Union afterwards" was "delusion and folly," Webster said, calling for "Liberty and Union, now and forever, one and inseparable!"
Lincoln likewise cast the Civil War as a test of whether any free nation could "long endure." If the nation perished from the earth, he held, so would the liberties that depend on it.
One hundred fifty years ago today, Lincoln began with not only the nation's conception in liberty, but its "proposition that all men are created equal." Having issued the Emancipation Proclamation that year, he haltingly came to recognize the imperative of expiating the original sin against that founding proposition - the sin willfully overlooked by Mencken's claim that the South fought for self-governance - through "a new birth of freedom."
A century afterward, Martin Luther King Jr. alluded to Lincoln's address in his own landmark "I Have a Dream" speech. Speaking in Gettysburg the same year, Vice President Lyndon Johnson presaged the civil-rights laws that sought to answer King's exhortations and finish the work of the emancipation. "The Negro says, 'Now.' Others say, 'Never,' " Johnson said. "The voice of responsible Americans - the voice of those who died here and the great man who spoke here - their voices say, 'Together.' There is no other way."
Perhaps Lincoln couldn't have imagined that the Union's progress would be such that he would one day be succeeded by a black man. But he would recognize much of today's rhetoric, having been accused of "politicizing" Gettysburg by attending the dedication of the soldiers' cemetery. Contemporary assessments of his address ranged from "perfect" to "silly."
Though we are fortunately far from the civil strife of that day, we never seem far from rancor and division. Even President Obama's decision not to attend the Gettysburg anniversary ceremonies has become another occasion for recriminations.
The words traded in these mostly partisan arguments dwarf Lincoln's only in number. They won't endure across scores and scores of years, belonging - like the man who uttered them and the duties to which they dedicate us - to the ages.