What is the appropriate way to mark the 150th anniversary of the political beginning of the American civil war? For about 300 people from Charleston, South Carolina, it seemed the best commemoration was a gala ball replete with champagne, period dress and dancing.

A ballroom full of white guests gathered last night, each paying $100 (£65), to mark the anniversary of 20 December 1860, the day that South Carolina became the first state in the US to declare secession from the Union in order to protect the right to slavery.

The evening began with a theatrical depiction of the secession convention in which 169 of the state's politicians voted unanimously to break with the Union and declare independence. The show ended with a rousing speech in which the show's narrator proclaimed: "The spirit of the south still stands. The spirit of freedom and honour gets passed from one generation to the next."

Then the cast of the show and the audience, largely dressed in period costume of Confederate uniform for men and hoop skirts in the style of Gone With the Wind for women, joined in a rendition of Dixie. "Look away! Look away! Look away! Dixie Land."

Most of those who attended the evening were directly descended from Confederate soldiers who fought against the north in the civil war. Though the historical consensus is that the south fought to preserve its right to slavery, and the economic riches that it brought, the prevailing opinion at the ball was that slavery had very little to do with it.

"For us the secession is not about a racial issue," said Michael Givens, the commander-in-chief of the Sons of Confederate Veterans, which sponsored the event. "We are not celebrating slavery, we are celebrating the courage and the tenacity of the people who were prepared to go out and defend their homes."

But outside the ballroom a crowd of about 150 protesters convened by the largest civil rights group in America, the NAACP, had a very different take on the proceedings. "What would happen if Japanese Americans decided to have a ball to celebrate Pearl Harbour?" Rev Nelson Rivers asked the protesters. "Or if German Americans celebrated the Holocaust? For African Americans tonight, that is exactly what's happening here."

The secession ball is just the first of numerous events that will commemorate aspects of the civil war over the coming four years. If this was at all representative, it suggests that the wounds inflicted one-and-a-half centuries ago are very far from being healed in modern America.