On Saturday, a group will gather in Alabama to mark the 150th anniversary of the inauguration of the first president of the Confederacy, 11 Southern slave states that left the US in 1860 and 1861. They say they are honouring their ancestors and their heritage but, as the BBC's Daniel Nasaw reports, critics view the group as celebrating slavery.
Under a bright Southern sky on Saturday, the Sons of Confederate Veterans will dress in period costume, including replica grey uniforms of the Confederate army, to commemorate the first raising of a national flag and the inauguration of a president.
They won't be saluting the familiar Stars and Stripes or honouring an occupant of the White House. Instead, they will pay tribute to the Confederate States of America, a political entity created after 11 states seceded from the US. That painful division led to the Civil War.
The event's organisers say that in addition to marking an important moment in US history, the commemoration is intended to instil a sense of pride in Southerners who they say have been taught to be ashamed of their heritage.
"It is imperative that this event be well attended," the Sons of Confederate Veterans Alabama division told supporters on its website.
"We must show the world that we will not permit the history and heritage of the Confederacy to be forgotten and unobserved.
"It is up to us to see that this history is remembered and portrayed in the right way."
But critics see Saturday's planned event differently - as an inappropriate and unsettling celebration of the enslavement of African Americans.
"Montgomery and Alabama will once again be cast as backwards, ignorant, racist hillbillies," wrote Montgomery Advertiser columnist Josh Moon in a recent article that called the planned rally a "national embarrassment" that would hold the state up to "ridicule".
"And we'll once again make it clear to everyone that some of us just can't let go of our racist past... The people who wore those Confederate uniforms were fighting for the wrong side, no matter what their personal intentions might have been."
The disagreement shows how the spasms of the Civil War continue to reverberate in US society almost a century-and-a-half after it ended with the surrender of the Confederacy, analysts say.
"It shows that we still haven't come quite to terms with the significance of slavery in American history," says prominent US historian Eric Foner, of Columbia University.
Historian Joshua Rothman, of the University of Alabama, says: "I don't think there's any possible way to disconnect the memory of the Confederacy from contemporary racial politics."
The US Civil War began on 12 April, 1861, when the new army of the Confederate States of America shelled US Fort Sumter, in a bay near Charleston, South Carolina.
By the time the war ended in April 1865, three million Americans had taken up arms and 620,000 had perished - 2% of the total population at the time.
Across the US, Americans have begun marking the 150th anniversaries of the events leading up to the fighting and, over the next four years, will commemorate virtually every battle, turning point, victory and surrender of the conflict.
The Confederacy's only president was Jefferson Davis, a Mississippi senator and former US secretary of war.
He was sworn into office on 18 February, 1861, in Montgomery, Alabama, and the Confederate flag was first flown soon after - events that will be re-enacted on Saturday at the state capitol building there.
"What we're trying to do is do a historically accurate portrayal of the inauguration," said Tom Strain, lieutenant commander of the Sons of Confederate Veterans Alabama division.
"The main focus of this sesquicentennial event... is to promote the legacy and the history of the Confederate States of America. That was a pivotal point in this nation's growth. It does not need to be forgotten."
Most historians say confederate politicians were unabashed about the prime motivation for secession - fear that the government in Washington led by President Abraham Lincoln would curtail slavery.
"They said: 'We are seceding because slavery is in danger'," Prof Foner said. "They didn't beat around the bush. They didn't feel slavery was safe in a union governed by the non-slaveholding states, and that is why they created the Confederacy."
But the Sons of Confederate Veterans reject this view.
"The victors write the history," said Chuck McMichael, former commander-in-chief of the group and a member of its governing council.
"If a nation invaded another nation for economic subjugation, they wouldn't portray themselves that way."
The Sons and other Confederate sympathisers say the Southern states seceded to protect "states rights", or in protest against import tariffs backed by northern industrial states.
Roughly 13% of the US population is African-American, with most of those tracing their ancestry to more than three million slaves living in the Confederate states at the start of the civil war.
"To me it's somewhat akin to celebrating the Holocaust," said Benard [sic] Simelton, president of the Alabama conference of the National Association for the Advancement of Colored People (NAACP), one of America's most prominent and oldest civil rights groups.
"The celebration of this means to me that we still have not come as far as we should have, as we think we have, in race relations in America.
"They wanted to keep African Americans in slavery. That's nothing to celebrate."