The recent march in Columbia, South Carolina, demanding the removal of the Confederate battle flag from atop the state Capitol is the latest episode in a long-running debate over the legacy of slavery and the Civil War. Those who seek to retain the flag have lately sought to reposition the Old South and the Confederacy in American memory. The Confederate flag, they tell us, represents not slavery but local identity, a way of life and respect for “heritage.” Some defenders of the flag go so far as to paint the pre-Civil War South as a multicultural paradise where black and white lived in harmony, and they claim that legions of slaves enlisted to fight for the Confederate cause.

There is no better way to honor one’s forebears than by taking their ideas seriously. To understand what the flag now flying in Columbia represents, one need only read the Declaration of the Immediate Causes of Secession, adopted by the South Carolina secession convention in December 1860. Modeled on the Declaration of Independence of 1776, it marshaled arguments that the authors hoped would inspire the rest of the South to secede.

South Carolina’s statesmen identified the preservation of slavery as their overriding concern. States’ rights and regional loyalty, often cited today as the real meaning of the Confederate flag, were invoked only as these doctrines protected slavery. The North, the declaration insisted, had “assumed the right of deciding on the propriety of our domestic institutions.” Abraham Lincoln, recently elected President, was a man “whose opinions and purposes are hostile to slavery” and under whose administration the institution would not be safe. “There can be but one end by the submission of the South to the rule of a sectional antislavery government at Washington,” the Declaration concluded: “the emancipation of the slaves of the South.”

Slavery, as Southern Vice President Alexander Stephens put it, was “the cornerstone” of the Confederacy. This does not mean that it was the only issue contributing to the coming of the Civil War. Nor does it suggest that the hundreds of thousands of men who fought under the Confederate banner, most of them nonslaveholders, were motivated exclusively by the desire to keep blacks in bondage. Yet to claim that Confederate soldiers went to war to protect their “way of life” conveniently forgets that this way of life was founded on slavery.

Slaves fully understood this. A few light-skinned blacks may have passed for white and joined the Southern Army. But the regiments of black Confederate troops one hears about of late exist only in myth or in the willful confusion of the Army’s black servants and laborers–slaves impressed into service by their masters–with combat soldiers. The reality is that hundreds of thousands of slaves eagerly sought their freedom by fleeing to Union lines and enlisting in the Union Army.

Despite claims that the flying of the Confederate flag is a tradition dating back to the Civil War, the fact is that for years after that devastating conflict few white Southerners felt any desire to memorialize the Confederacy. The cult of the Lost Cause did not flourish until the 1890s, just as a new system of racial inequality resting on disenfranchisement and segregation was being created throughout the South.

Not until a century after the Civil War did South Carolina’s white leaders feel the need to display the flag above the Capitol, for reasons that had more to do with the 1960s than the 1860s. In March 1961, as the Civil War centennial celebration began in Charleston, a black member of the New Jersey delegation was denied admission to the headquarters hotel. President Kennedy then transferred the meeting to a nearby naval base, whereupon the South Carolina delegation seceded, holding its own “Confederate States Centennial Conference,” with the Confederate flag prominently displayed. A year later, the flag was mounted above the state Capitol as a gesture of defiance against the civil rights movement. To the flag’s previous association with slavery was now added a connotation of racial segregation.

Public monuments, historical markers and symbols reflect what a society thinks should be commemorated. One hopes that when the Confederate flag comes down, as now seems inevitable, the myths that prevent a full acknowledgment of the central place of slavery and racial injustice in our nation’s history will also be laid to rest.