FREDERICKSBURG, Va. -- Sliding down a Rappahannock riverbank on the seat of his $450 wool pants, Brig. Gen. Michael Kraus understood the Union Army's problem with pontoons.
In November 1862, Gen. Ambrose Burnside missed his chance to surprise Robert E. Lee's Army of Northern Virginia here because pieces of his floating bridges were stuck on a train.
One hundred fifty years later, Mr. Kraus and 600 other Union re-enactors found their pontoon bridge 5 feet too short. As icy water filled their reproduction 19th-century boots, they knew that once again, it would be a bad day for the boys in blue.
Other than the river crossing, last weekend's "Fire on the Rappahannock," the 150th anniversary re-enactment of the Battle of Fredericksburg, went pretty much according to plan: The Union's Army of the Potomac met fierce resistance from about 500 Confederates at the City Dock and exchanged fire while marching down Sophia Street, stopping to loot a few houses on the way. Turning the corner on Hanover Street, the two armies battled for every foot of asphalt, each leaving about a dozen comrades sprawled by crosswalks and in doorways. Amid cries of "Shoot 'em!" and "Damn Yankees" from the mostly partisan crowd, the Rebels surrendered and broke for lunch.
For two hours, tourists and re-enactors packed this historic town's outdoor cafes and restaurants, enjoying unusually warm December weather and the chance to get their pictures taken with Gens. Lee and James Longstreet on one corner, Burnside on another. At 2:30 p.m., Union forces were on the march again, with a fire engine escort, heading down Hanover toward Trench Hill for the battle's climax, the assault on Marye's Heights. Bystanders on sidewalks and front lawns took turns chatting with and teasing the Northern aggressors:
"Where'd they go? I'd hide behind a car, too, if I was a Yankee," one man said.
Volleys started as Yankee infantry slowly chased Rebels back to their replica stone wall and a hillside behind Mary Washington University, stand-ins for the nearby battlefield.
In this educational and yes, entertaining re-enactment, there were few times in which onlookers truly felt transported back to Dec. 13, 1862, when Gen. Burnside's indecision, bad luck and poor battle plan caused him to lose nearly a third of the 40,000 men he threw at an impregnable position held by 6,000 Rebels.
One such moment came when the first wave of blue coats ran up the hill toward ranks of grays waiting within sight of the real Sunken Road and Marye's Heights. A few pops and Rebel yells from behind the stone wall suddenly became a steady roar of gunfire. A half-dozen Yankees collapsed, groaning, as their comrades took aim at the gray cloud rising from the wall, then dived for cover. Some lay on their backs, tearing paper cartridges with their teeth and frantically loading powder for another shot.
It was horrible -- and fascinating -- to see each blue wave surge and recede, leaving behind a few more bodies like pebbles on a grassy beach. As the piles of human pebbles grew, they became a low blue wall mirroring the stone one 50 yards away, animated shooters hiding behind inanimate ones.
For the re-enactors, the fighting is mostly about putting on a good show.
"Take hits! Take casualties!" Mr. Kraus and other officers shouted to the Union infantry, hoping spectators didn't hear. At the real Marye's Heights that day, more than 8,000 Union troops were killed, wounded or captured. The bodies were so thick that the ground turned blue, observers said.
"You guys finally figured out how to take hits!" a Confederate officer said to Mr. Kraus afterward.
Another defining moment -- if your last name is Kirkland (see related story) -- came at the end of the battle, when four "Angels of Marye's Heights" emerged from behind the wall to offer water and aid to wounded Union soldiers. Other Confederates "looting" the bodies weren't as noticeable.
Then the battlefield was quiet as a lone bugle played Taps, mourning the nearly 1,900 men who died here 150 years ago. After one silent moment, Union "casualties" leaped to their feet, drawing great applause, and rushed the wall one more time to shake hands and take pictures with fellow re-enactors. Spectators rushed the battlefield, too, to take photos, ask questions, and debrief friends and family members in uniform.
Severn Welsh, 6, of Purcellville, Va., closely questioned Greg Stull, who was dressed as Gen. John Bell Hood of Texas, about the minimum age required to dress in period costume and rush into the teeth of mostly middle-aged musket fire. He was clearly dismayed when Mr. Stull told him he had to be at least 12 to be a Civil War drummer.
"He just loves it," said Jacquelynn Hollman, smiling at her son in a Union private's cap. Despite his current quarters in northern Virginia, "he's a Yankee," she said.
Proving that Civil War re-enactors ignore geographical boundaries, Mr. Stull lives in Bernville, Berks County, and normally portrays Gen. Leonidas Polk of Tennessee as a member of Lee's Lieutenants. His wife Sherri, who was in period dress as a civilian, sometimes plays the part of a soldier on a cannon crew.
"Today I fought for the Confederates but most of the time, I'm Union," she said.
Mrs. Stull was one of several women who joined their husbands last weekend. Mr. Kraus, head of the 116th Pennsylvania and curator of Soldiers and Sailors Hall, said his group currently has no women re-enactors.
"We have a 10-foot rule. If you can fool us at 10 feet, you're in," he said, laughing.
Gary and Mark Hertweck, brothers from Indiana Township, followed Mr. Kraus into the 116th 27 years ago, "We come to have fun, burn some powder and go home," said Gary, who now lives in Canton, Ohio.
Chris Sedlak, 38, of Banksville, who served a tour in Iraq with the Army, said there is a similar sense of camaraderie within the 9th Pennsylvania, known as the Iron City Guards. He also likes the simplicity of cooking over a campfire and eating by candlelight.
"I really appreciate the magic moments when you feel you're back there," he said. "Some of us feel like we're stuck in the 21st century."
Most of the re-enactors interviewed said they would be in Gettysburg next summer but not necessarily at the biggest event in early July. Many would rather participate in the Blue-Gray Alliance re-enactment the week before for more hard-core "campaigners" or the weeklong Union march from Chantilly, Va., to Gettysburg.
With so many 150th battle anniversaries coming up in the next few years, re-enactment organizers worry that the ranks of the blue and gray are getting grayer just as interest is growing.
"I'm close to 60 and that's 30 years too old to be a soldier," said Michael Schaffner of Arlington, Va., who helped to organize "Fire on the Rappahannock."
First-year re-enactors such as Karin and Karina Mendoza of King George, Va., who were joined by Karina's 12-year-old brother, Douglas, give Mr. Schaffner hope that the hobby will survive the war's 150th anniversary, after which many baby boomers will likely hang up their boots and muskets. Mr. Schaffner started 12 years ago after a friend told him about re-enacting.
"I thought some day I'll try that. Then I realized some day better be today if I want to wear wool in the summer."