For the third year in a row, on the second Saturday of December, I traveled to Arlington National Cemetery to place Christmas wreaths on the graves of the fallen.

I'm late to the party, as some people have been coming since the early '90s, when Morrill Worcester, a wreath wholesaler from Maine, showed up at Arlington with his first tractor-trailer load of that season's leftovers.

That year, as Worcester told the crowd at Arlington last weekend, the reaction at the cemetery was part "You want to do what?" and "Who's gonna clean this up?" Then, a handful of volunteers spent about six hours placing 5,000 wreaths.

Times have definitely changed.

This year, about 6,000 volunteers gathered at the McClellan Arch in the cold, early-morning hours to place 15,000 donated wreaths in five sections of Arlington. It would take less than two hours. The cemetery's superintendent and a Florida congressman welcomed Worcester and his wife, Karen, their three truckloads of wreaths, and the crowd.

And what was once a generous, spur-of-the-moment kindness has turned into a year-round effort for Wreaths Across America, the nonprofit arm of Worcester Wreath Co. This year, according to Wayne Merritt, who runs the nonprofit, the group collected donations for 150,000 wreaths that were used at wreath-laying ceremonies at 405 military cemeteries and monuments around the world, and on at least one U.S. Navy ship at sea.

Not all gatherings are as big as Arlington, but every site gets at least seven wreaths - representing the Army, Navy, Marines, Air Force, Coast Guard, Merchant Marine and POW/MIAs. The ceremonies are all timed to coincide with the noon placement of the day's final wreath at the Tomb of the Unknown Soldier.

Cars, trucks, and buses full of volunteers were already lined up outside Arlington's gates at 7 a.m. - and some were still waiting to get in long after the wreaths had been distributed. When I first wrote about the Worcesters in 2007, about 600 volunteers were helping place wreaths. But it was a weekday event then, Merritt points out, and before a picture of wreaths atop snow-covered Arlington graves began circulating on the Internet. Word spread, and the number of volunteers has grown steadily since.

As people gather, it's an odd mix of solemn occasion, celebration, and reunion. To be there seems almost a duty, though certainly not a burden. It's a privilege, an honor.

Civilians and vets mingle with service members in uniform. There are couples, old and young, families with babies. A group of Catholic University alums. And other groups with their names emblazoned on leather jackets: the Patriot Guard, the Christian Motorcycle Association, Leathernecks Nation.

There are conversation and laughter as people wait to begin, but respect and dignity are paramount. Yes, this is a tourist destination in the nation's capital, but it's also an active cemetery, still sadly in the business of burying the nation's sons and daughters killed in battle. We, the day's visitors, are among people in mourning. We are intruding, yet welcome.

Ruth Stonesifer of Bucks County lost her son Kristofor, a vegan, a philosophy major, and an Army Ranger, in a helicopter accident in Pakistan a month after 9/11. As president of American Gold Star Mothers, Stonesifer let those assembled in Arlington know what their presence meant.

Despite the initial support when a soldier is killed, Stonesifer told the crowd, eventually the family panics, wondering if anyone will remember their loved one's sacrifice. But that morning in Arlington, she said later in an interview, "absolutely dispelled the fear that our sons and daughters will be forgotten.

"They may not know my son's story, but they showed up on a perfectly beautiful Saturday and paid homage."

I place my first wreath in Section 60, where the casualties from the current wars are laid to rest - some burials so recent that the traditional white headstone has not yet arrived. Families are there that day, decorating graves with quilts, stockings, photos - and 1,000 wreaths from Wreaths Across America. They are holding each other. Some are crying.

Spec. Stephan Mace of Virginia was killed only two months ago, on Oct. 3, when Taliban insurgents attacked his post, Forward Operating Base Keating, in Afghanistan's Kamdesh district. He was 21.

My second wreath went on the grave of Col. Joseph D. Aronson, a Pennsylvanian who served in the medical corps during both world wars. He died in 1958, age 69. His wife, Charlotte, was buried next to him 24 years later.

In the book, Lincoln at Gettysburg, author Garry Wills wrote about the 19th-century movement that sought to make cemeteries more than a place for the dead, but actually "schools of life." Supreme Court Justice Joseph Story summed up the effort - and a Saturday morning at Arlington - in an 1831 speech:

"Our cemeteries, rightly selected and properly arranged, may be made subservient to some of the highest purposes of religion and human duty. They may preach lessons to which none may refuse to listen and which all that live must hear. Truths may be there felt and taught, in the silence of our own meditations, more persuasive and more enduring than ever flowed from human lips."