"I should like to know if taking this old Declaration of Independence, which declares that all men are equal upon principle and making exceptions to it," asked Abraham Lincoln in July 1858, "where will it stop? If one man says it does not mean a negro, why not another say it does not mean some other man? If that declaration is not the truth, let us get the Statute book, in which we find it, and tear it out!" Speaking to Chicago supporters of his campaign against Senator Stephen A. Douglas, Lincoln repeated himself: "If it is not true, let us tear it out!"

In the wake of the proslavery Kansas-Nebraska Act in 1854, Lincoln worried that the Declaration's commitment to human equality and freedom was under attack. He was not a fan of fireworks. But what he particularly disliked was that the "self-evident truths" of the Declaration of Independence had been effectively replaced in the mid-19th century by noisy celebrations on July 4.

"On the question of liberty, as a principle, we are not what we have been," Lincoln wrote a Kentucky lawyer in the summer of 1855. "When we were the political slaves of King George, and wanted to be free, we called the maxim that 'all men are created equal' a self evident truth; but now when we have grown fat, and have lost all dread of being slaves ourselves, we have become so greedy to be masters that we call the same maxim 'a self-evident lie.' The fourth of July has not quite dwindled away; it is still a great day -- for burning fire-crackers!!!"

Nine days later, Lincoln wrote his best friend, also a Kentuckian: "Our progress in degeneracy appears to me to be pretty rapid. As a nation, we began by declaring that 'all men are created equal.' We now practically read it 'all men are created equal, except negroes.'"

Lincoln revered the principles of the Declaration. On July 6, 1852, Lincoln had begun a eulogy for Henry Clay, Kentucky's most famous son: "On the fourth day of July, 1776, the people of a few feeble and oppressed colonies of Great Britain, inhabiting a portion of the Atlantic coast of North America, publicly declared their national independence and made their appeal to the justice of their cause, and to the God of battles, for the maintainance [sic] of that declaration. That people were few in numbers, and without resources, save only their own wise heads and stout hearts." Lincoln believed the congressional Act of Independence of 1776 was the official beginning and foundation of the American republic.

On November 19, 1863 at Gettysburg, President Lincoln began: "Four score and seven years ago our fathers brought forth, on this continent, a new nation, conceived in Liberty, and dedicated to the proposition that all men are created equal." That is, in 1776. Lincoln then noted that the Civil War tested "whether that nation, or any nation so conceived, and so dedicated, can long endure." The principles of liberty and equality -- that Lincoln saw under attack during the slavery controversy in the 1850s -- were at stake, not only for America, but for the whole world.

The Battle of Gettysburg had been fought on July 1-3, 1863. On July 4, Vicksburg, the last Confederate stronghold on the Mississippi, surrendered. The significance of that date was not lost on President Lincoln in Washington. He told a crowd outside the White House that "a succession of battles in Pennsylvania, near to us, through three days, so rapidly fought that they might be called one great battle on the 1st, 2d and 3d of the month of July; and on the 4th the cohorts of those who opposed the declaration that all men are created equal, 'turned tail' and ran."

Lincoln remained steadfast in his embrace of the Declaration of Independence throughout his presidency. As he had urged listeners in 1858: "Return to the foundation whose waters spring close by the blood of the Revolution. Think nothing of me; take no thought for the political fate of any man whomsoever, but come back to the truths that are in the Declaration of Independence." 

Lewis E. Lehrman is chairman of the Lincoln Institute and author of "Lincoln at Peoria: The Turning Point."