The debate that still divides a nation – 150 years on

David Usborne reports from Charleston, South Carolina, where a ball to mark the anniversary of the American Civil War has been mired in accusations of racism

The pantomime season only lasted a day in Charleston, South Carolina this year, but no one can say the amateur dramatics – and the audience participation – did not have a special intensity about them. The American Civil War wasn't about slavery, honestly. Oh, yes it was! Oh, no it wasn't! Oh, yes it was!

This was the scene, more or less, at the city's municipal auditorium on Monday night, 150 years to the day after the signing of the declaration of secession from the Union by South Carolina, an act of mutiny that sowed the seeds of Confederacy and set in motion a conflict that killed roughly 620,000 Americans.

Inside the hall, 200-odd guests, all white and some in period costume, gathered to see a re-enactment of the signing of the secession document. When it was over, they instinctively joined the cast in singing the anthem of the South, "Dixie", before repairing to an adjoining hall for dinner and dancing.

Outside, a racially mixed crowd of about 100 held electric candles aloft at dusk to begin a protest march through downtown Charleston, singing the songs of Selma and Montgomery, including "We Shall Overcome". Each camp thus indulged in their forms of theatre before taking to their beds.

But the US is only at the beginning of a four-year stretch of events to commemorate the Civil War, which will peak with the anniversary in November 2013 of Abraham Lincoln's "Gettysburg Address". The mostly polite battle in Charleston will be played out throughout the intervening period - and it may not always be so controlled. If the Civil War was about the South protecting and eventually losing its right to practise slavery, what place has this nostalgia?

"The South lost the war but they really won it, because they continue to say the war was not about slavery, which is not true of course," argued Blain Roberts, an assistant professor of history at California State University, who attended Monday night's South Carolina Secession Gala to conduct research for a book. "They won the memory of the war, at least."

Also in the hall to observe rather than participate – you could tell because she was not in the hooped skirt costume of Gone with the Wind – was Cynthia Cowan, a Masters student at Houston University, who was more blunt. Those who had bought the $100 (£65) tickets for the evening were "wilfully ignorant or proudly nonchalant" of the offence they would inevitably cause, she said.

If the organisers of the Secession Gala felt the heat of inquiring reporters and noisy protesters, for the guests, the atmosphere, fuelled by mint julep cocktails and bowls of shrimp and grits, was more delirious than defensive. Never mind the breeze-block walls and lino-tile floor, or that the furniture for the re-enactment was more 1970s office than 1860s ceremonial.

Proud is how most seemed to feel. Donna Simpson was so because her fifth great-grandfather was the uncle of Robert E Lee, the legendary Confederate General. Her husband, Mark, is the commander, South Carolina, of the Sons of Confederate Veterans, a charity organisation. "We celebrate life," he said, responding to the claims that the event was feting slavery. "We are glad that slavery came to an end."

To the music of a band aptly called Un-Reconstructed, the Simpsons and other couples in their finery joined the Grand March, entering the hall in pairs with as much Scarlett O'Hara pomp as they could muster, and bowing before their hosts – the national commander-in-chief of the Sons of Confederate Veterans, Michael Givens, and his wife – beneath the stage. The subsequent hours of dancing were interrupted only once when a plastic oak tree draped with fake Spanish moss toppled over after being sideswiped by a damsel who had briefly forgotten how impractical those old-fashioned skirts really were.

Mr Givens found all the questions about slavery pesky. "We are not celebrating that and this is not malicious," he said. "It's about honouring our forefathers for their tenacity. It's about the bravery and courage of our ancestors." Exasperated by the focus on slavery, he then asked: "Can you not be selective about what you are nostalgic about?"

On hand to galvanise the protesters was a local clergyman, the Rev Nelson Rivers. "If Japanese Americans chose to celebrate Pearl Harbour this way it would be outrageous and would not be allowed to occur and that is what is happening here tonight," he said into a megaphone.

Tangee Rice, 57, an African American woman, drove 120 miles to the march and was wearing the same hat her grandfather had worn marching with Martin Luther King. "The Confederacy is not something to celebrate," she said. "It's just not right." About those re-enacting the start of the Civil War, she said: "They still haven't grown out of it, and it's really sad."

Argument about what sparked the War – Mr Givens and Mr Simpson will tell you it was about tariffs and taxes imposed by the North – will never end. But the harder issue, which Ms Rice raises, is this: Yes, America is a much different place now, but does the nostalgia conceal a lingering racism, even a yearning for history to be rewound?

"I am a proud American and I wouldn't want our country to go through that again," Bill Norris, 60, a maker of banking machinery and gala guest, said. Yet, he wonders, what if the Confederacy had won? "A part of me does regret it didn't happen," he said. "I believe at some point in dividing the country. We would be better able to govern ourselves in smaller groups. Why should New Yorkers be able to influence government in South Carolina?"

The cord between today and the old conflict remains for some in the South.

Charleston factfile

* In 1860 the population was 58 per cent white and 42 per cent black (a few years earlier, black slaves outnumbered whites). Today it is 45 per cent white and 43.6 per cent black with small Asian-American and Hispanic groups.

* In 1860 the economy was based on manufacturing though in decline as new railroads diverted trade. Half the city's wealth was held by 155 leading citizens. Modern Charleston has a thriving tourist industry and several large IT businesses.

* In 1859, the population was 40,522. It was the 22nd largest US city. Now, despite tripling in size, it ranks 246.

* South Carolina is the fifth poorest state in the US. In 1860 it was the third wealthiest state.