In March 1865, with the Civil War's final days in view, President Abraham Lincoln said plainly in his Second Inaugural Address that "all knew" that slavery "was somehow the cause of the war." Today, as the nation commemorates the war's sesquicentennial, the war's fundamental cause—slavery—is obscured in mythmaking and selective memory. It's time we get it right. Only by facing the past honestly can we as a nation progress toward a more perfect union. To that end, we need a clear understanding of the core issue, an understanding that goes beyond hackneyed myths and cloying appeals to regional vanities.  

Was the war fought over states' rights? Yes, but states' rights for what? Over Fifth Amendment property rights? Sure, but property rights regarding what?  Over regional economics? Of course, but what was the foundation of the South's economy? No matter how one cuts it, the unequivocal answer to each question is slavery—or, more precisely, the expansion of slavery into the western territories. Without slavery, there would have been no war between North and South—period.

This fact was vividly clear to the men who chose to secede from the Union. South Carolina's secession manifesto of December 1860, for example, repeatedly railed against the Union's interference in slavery and rightful "property." Mississippi's declaration made clear in the first paragraph that the decision to secede was "thoroughly identified with the institution of slavery." When Confederate leaders wrote their national constitution in March 1861, they mentioned slavery no fewer than nine times, including Article I, Section 9, which stated that "No bill of attainder, ex-post facto law, or law denying or impairing the right of property in negro slaves shall be passed." And Confederate currencies often depicted laboring slaves.

Not only must we recognize that the war was fundamentally about slavery; we must also reflect soberly on the nature of slavery. It is easy to let the word "slavery" pass one's lips without appreciating the consequences of that profound imbalance of power: the violence, the sexual abuse and rape, the routine selling of human beings as one would sell a mule. Imagine a knock at your door this evening by someone who has come to take away your spouse, child, sibling, or parent—forever. That was the reality of the Civil War's fundamental cause.

Commemorations such as "Confederate History Months" typically ignore or marginalize these harsh truths. While it is entirely appropriate to memorialize the sacrifices and hardships of millions of Confederate soldiers and households, too often those solemn intentions get lost in patriotic excess and vague notions of "Confederate heritage." And whose heritage is it, anyway? Several of the Deep South states had slave populations that outnumbered white residents.

Today, in the former Confederate states it is common to encounter the most popular symbol of Civil War "heritage," the Confederate battle flag. One can see it displayed on vehicles and clothing and, perhaps most provocatively, on the grounds of the South Carolina statehouse. It also influences the design of several current state flags of the former Confederacy. Regrettably, arguments defending public displays of the flag seldom grapple with the essential truth behind its creation.

In light of the persistent and often deliberate confusion over the Civil War's fundamental cause, it is instructive to return to Lincoln's words in his 1863 Gettysburg Address. By beginning his memorial speech with "Four score and seven years ago," Lincoln returned, not to the U.S. Constitution—whose compromises allowed for slavery's continuation—but rather to the Declaration of Independence, which boldly declared that all men are created equal. The president concluded by solemnly urging the nation to dedicate itself to "a new birth of freedom." The point was unmistakable: This new birth of freedom was necessitated by a civil war brought on by slavery.

For Americans who have ignored the undeniable historical truth of slavery's central role in the coming of the Civil War, may they be guided in the future by what Lincoln called the better angels of our nature.

This piece was distributed for non-exclusive use by the History News Service, an informal syndicate of professional historians who seek to improve the public's understanding of current events by setting these events in their historical contexts. The article may be republished as long as both the author and the History News Service are clearly credited.