Chris DeRose is a historian, and is the New York Times bestselling author of The Presidents’ War, Congressman Lincoln, and Founding Rivals. He works as a lawyer in Arizona.

I will always wonder what America could have been, if not for slavery.

It was a tragic inheritance from colonial days that became a congenital defect upon independence. A new nation, formed on the principle of equality before the law, began with two radically different sets of rights for its residents, depending on skin colour. Slavery frustrated our efforts to form a constitution and polarised our politics from the outset. Just as the economic incentive for slavery waned and the institution appeared to be dying out, the cotton gin made it the most profitable enterprise in the world, more valuable than all the industrial assets of the north.

The issue was ultimately not settled through the political process, but by arms. Calling themselves the Confederate States of America, a group of states claimed to have seceded from the Union, and raised armies for the purpose of making it a reality.

They were absolutely clear in their purpose – to protect and advance the institution of slavery. Thousands of pages of debates and declarations testify to slavery as the cause of the war (five states published declarations lest they be misunderstood). But in after years, this was obscured by a successful effort on the part of the defeated party and their children and grandchildren. Among the many myths perpetuated is that slavery was but one of many causes. Freed from the truth of the war’s origin, partisans argue that Confederates and their military leaders were great men who fought a “Lost Cause” for a noble purpose.

This is a lie. And it cannot be ignored as a harmless one. It’s a lie that dishonours the hundreds of thousands who died fighting to preserve the Union by equating them with the people who directed their greatest efforts in life to try and end it.

Yet Confederates are honoured by having their names on streets, schools, monuments, and even military bases. Is there another country in the history of the world that glorifies the people who did their best to destroy it?

It’s perverse to celebrate treason against the United States for the purpose of keeping millions of human beings as property. And, generally speaking, it’s time for these monuments to go.

You may well wonder why this is a minority viewpoint in my country.

First, millions of Americans have relatives who fought for the Confederacy. They know their names, and often have photographs, letters, and treasured items belonging to them. If you could choose to believe that your ancestor fought for something better than slavery, wouldn’t you?

Second, even if one can accept the cause of the war, they want to honour the valour of individual soldiers. This is a compelling argument. The average Confederate soldier did not own slaves, and could have been fighting for any number of reasons. These include having been conscripted and because a hostile army was in their homeland. Those are both good reasons from my vantage point. Indeed, generic memorials to Confederate war dead are less problematic. But we must remember that acts of bravery, heroism, and sacrifice were performed to advance every ignoble cause. And as General Ulysses Grant put it, nobody ever fought for a worse cause than the Confederacy.

Third, there are people who know exactly what the war was about and support these monuments for that reason. Confederate tributes are almost all from the 20th century, and multiplied every time the civil rights movement made advances. One of the most famous of these – the Confederate battle flag atop the South Carolina Capitol – was first flown in 1961. The Robert E. Lee statue that ostensibly touched off the march in Charlottesville was commissioned in 1917, as the nation’s largest civil rights organisation was formed and segregation was under assault in the courts.

We can’t change the past, or what our ancestors may have done, but we can decide who we want to be and what kind of future we want to have. For that reason, no school, street, or military base should be named after any Confederate leader, and no unit of government in the United States should fly the Confederate battle flag. Monuments at battlefields should remain, as they serve a valuable educational purpose and a tribute to the fallen.

Statues of Robert E. Lee, who violated his military oath to join the rebellion, and his fellow generals, must go. People have suggested that George Washington and Thomas Jefferson should be defrocked by the same standard. Untrue. While America’s Founders may have had beliefs that didn’t stand the test of time, and while some of them owned slaves, this is not the standard for whether they are commemorated. When you see an honour to Washington, you know that it celebrates his role in winning America’s independence and serving as its first president, refusing to be a king. Lee, Stonewall Jackson, Jefferson Davis, and the rest are commemorated for one thing and one thing only: attempting to destroy their country in the name of slavery. That is why they need to make their way from public places of honour to museums.

Critics have claimed that we intend to erase history. This is about correcting history. I’d gladly trade every memorial for a monument to the victims of slavery. So far, no takers.