Charleston kicked off America's national Civil War remembrance this morning with a simple mortar salvo fired toward Fort Sumter, launching four years of events to come around the country.

At 6:45 a.m. a thunderous boom rattled houses around James Island where the flash of a mortar fired from Fort Johnson on took the nation back 150 years.

On cue, batteries of cannons stationed around Charleston Harbor -- and pushed into place earlier this week by re-enactors -- opened up, marking their many positions by puffs of distant white smoke.

A "star shell" was also fired into the dawn sky -- looking more like a bottle rocket than a powerful wartime burst -- as a visible signal to re-enactors to begin re-living the attack that started the war on April 12, 1861. The flare seemed to rise not much higher than 40 yards.

A representative of the pyrotechnics company behind the shot later explained the burst was intentionally weak, as a safety precaution to the crowds of people on hand to witness the waterfront ceremony.

Some of those in attendance could trace their ancestry to those who were in Charleston during the attack, among them John Hugh Farley, of Roswell, Ga.. His distant relative, Henry Saxon Farley, took part in the original mortar launch.

Farley today called the event a mixed blessing because it brings memories "from way back. But it helps us look at history and learn from history," he added.

Some of the re-enactors said they would not have missed being part of Charleston's lead-off sesquicentennial event for anything.

"This is one of the four pivotal events of U.S. history," said Mike Lussier, of Charleston, a member of the mortar crew. He put the bombardment of Fort Sumter in company with July 4, December 7, and 9/11.

One of the main speakers at Fort Johnson was state Sen. Glenn McConnell, R-Charleston, who recognized the contributions of those who took part in the war that took more than 600,000 lives. "From their long and costly war they bestowed upon this country enduring peace," he said.

Cannons set up around the harbor will fire throughout the day in recongnition of the bombardment. "This was history, again, in the making," McConnell said of the ceremony.

Prior to the James Island gathering, several hundred people gathered along the railings at the High Battery downtown to commemorate the exact moment the Confederacy fired the first shot at Fort Sumter. Instead of re-enacting the moment with cannons and fireworks, organizers went visual, as a single 7,000-watt beam of light emitted from the Forth, stretching to the sky.

Shortly after 4:30 a.m., it was joined by a second beam, symbolic of the split between North and South.