What caused the Civil War? That seems like the sort of simple, straightforward question that any elementary school child should be able to answer. Yet many Americans—including, mostly, my fellow Southerners—claim that that the cause was economic or state’s rights or just about anything other than slavery.

But slavery was indisputably the primary cause, explains Colonel Ty Seidule, Professor of History at the United States Military Academy at West Point.

The abolition of slavery was the single greatest act of liberty-promotion in the history of America. Because of that fact, it’s natural for people who love freedom, love tradition, and love the South towant to believe that the continued enslavement of our neighborscould not have possibly been the motivation for succession. But we should love truth even more than liberty and heritage, which is why we should not only acknowledge the truth about the cause of the war but be thankful that the Confederacy lost and that freedom won.