Why do we celebrate the Fourth of July? For all too many Americans, it is just another summer holiday, albeit one that usually features fireworks. Of course, most Americans dimly recollect that it was on this day sometime in the distant past that Americans declared their independence from Great Britain, but they seldom stop to reflect upon the true revolution that the Fourth of July signifies: the Declaration of Independence and the creation of a nation based on a universal idea.

The word "nation" comes from the Latin natio, a noun derived from a form of the verb meaning "to be born." It has traditionally meant a grouping based on such tangibles as race or blood. National movements since the nineteenth century have usually had as their goal the creation of a territorial state encompassing those possessing that common identity. It is this understanding of nationhood that Hitler reflected when he reputedly claimed that the United States was "not a nation (Volk), but a hodgepodge (mischung)." But it is the Declaration, not race and blood, that establishes American nationhood, constituting "the mystic chords of memory, stretching from every battle-field, and patriot grave, to every living heart and hearthstone, all over this broad land…"

As Abraham Lincoln remarked in 1859: "All honor to Jefferson—to the man who, in the concrete pressure of a struggle for national independence by a single people, had the coolness, forecast, and capacity to introduce into a merely revolutionary document, an abstract truth, applicable to all men and all times, and so embalm it there, that to-day, and in all coming days, it shall be a rebuke and a stumbling-block to the very harbingers of re-appearing tyranny and oppression."

In a speech delivered just after Independence Day 1858, Lincoln clarified the link between the Declaration and American nationhood. His argument is one we should ponder at a time when "multiculturalists" are advancing the view that the US is not a land of free individuals but instead a conglomeration of discrete racial and ethnic groups.

When we celebrate the Fourth of July, Lincoln told his listeners in Chicago, we celebrate the founders, "our fathers and grandfathers," those "iron men…But after we have done this we have not yet reached the whole. There is something else connected with it. We have besides these men—descended by blood from our ancestors—among us perhaps half our people who are not descendants at all of these men, they are men who have come from Europe—German, Irish, French and Scandinavian—…finding themselves our equals in all things. If they look back through this history to trace their connection with those days by blood, they find they have none, they cannot carry themselves back into that glorious epoch and make themselves feel they are part of us, but when they look through that old Declaration of Independence they find that those old men say that ’We hold these truths to be self-evident, that all men are created equal,’ and then they feel that the moral sentiment taught in that day evidences their relation to those men, that it is the father of all moral principle in them, and that they have a right to claim it as though they were blood of the blood, and flesh of the flesh of the men who wrote that Declaration, and so they are."

In Lincoln’s view, America is a nation by virtue of its commitment to the principle of equality, by which he meant simply the idea that no person has the right to rule over another without the latter’s consent. For Lincoln, what made the United States unique, and constituted the foundation of American nationhood, was the incorporation of this moral principle into the Union. This belief lay at the heart of his opposition to slavery, an affront to the very idea of republican government.

Of course, defenders of slavery such as South Carolina Senator John C. Calhoun, Georgia Senator Alexander Stephens, and Chief Justice Roger Taney and "don’t-care" politicians such as Illinois Senator Stephen Douglas disagreed. Taney and Douglas argued that Jefferson did not mean to include blacks when he wrote that all men are created equal. Calhoun and Stephens contended that he did mean to include them but that his view was false.

The irony is that while Lincoln’s view prevailed with the Union triumph in the Civil War and was subsequently incorporated in the Constitution via the 13th and 14th Amendments, it is the view of Taney et al that often predominates today. The rejection of Lincoln’s view of American nationhood is visible on both today’s political left and political right.

The main threat to American nationhood from the left is multiculturalism, a notion that would appeal to Hitler: the idea that race defines destiny, that blood determines who we are and what we can become. Multiculturalists reject the principles of the Declaration because they see them as, at best, "cultural imperialism" and at worst, racism.

To argue against multiculturalism is not to reject ethnic pride. I like to joke with my students that since Mackubin is a sept of the Clan Buchanan, whenever I hear a bagpipe, the hair on the back of my neck bristles and I want to kill an Englishman. But then I realize that other of my forebears were English and Welsh, so I would have to kill myself.

In America, ethnicity is an indicator of whence we have come, not where we are going. It is precisely the rejection of ethnic politics and the embrace of politics based on individuality and equality that have created the conditions of civility and domestic tranquillity upon which American strength and prosperity rest. The increasing hyphenation of America bodes ill for these conditions.

The threat to American nationhood from the right is nativism, which arises from the same soil as multiculturalism. Rather than invoking separation, nativism calls for exclusion and restriction on the basis of a distinction between "us" and "them." From the "Know-Nothings" of the American Party before the Civil War to today’s xenophobes, there have been those who have treated immigrants as the enemy, rejecting the idea of the United States as a polity based on a principle rather than on race and blood.

Of course, the Founders did not believe, as do some of today’s liberals, that there is an absolute "right" to immigration and US citizenship. They held that since America is a polity based on consent as well as equality, citizens have certain rights against foreigners, one of which is the right to exclude immigrants based on a judgment regarding the character of those to be admitted. But the Founders did not fear "outsiders" per se, demanding only that they abide by the law. As Washington wrote in 1790 to the Hebrew Congregation of Newport, "…happily, the Government of the United States, which gives to bigotry no sanction, to persecution no assistance, requires only that they who live under its protection should demean themselves as good citizens…"

As we celebrate the Fourth of July next week, we should reflect on the uniqueness of American nationhood arising from the Declaration of Independence. We have, of course, not always lived up to the "self-evident truths" articulated in this document, as the history of slavery attests. But these truths constitutes what Lincoln called the "central idea" of the American Republic without which republican government will fail and the American nation will dissolve.

Mackubin Thomas Owens is an Adjunct Fellow at the Ashbrook Center for Public Affairs at Ashland University.