LEWISTON — The Wreaths Across America convoy will stop at Thomas J. McMahon Elementary School on the first day of its weeklong trip to Arlington National Cemetery to lay 250,000 wreaths on veterans’ graves.

The convoy of more than a dozen tractor-trailers, several police escorts and dozens of support vehicles will arrive at McMahon School at 151 North Temple St. at 2:35 p.m. on Sunday, Dec. 11. A ceremony will be held before the caravan continues its journey at 4:30 p.m.

McMahon School is named for Spc. Thomas McMahon, a Lewiston High School graduate who was killed in Vietnam in 1969 and received the Medal of Honor. His brother, Michael, and the McMahon family will greet the arrival of the caravan.

Referred to as the nation’s longest veterans’ parade, the mission of Wreaths Across America is to “remember the fallen, honor those that serve and their families and teach the next generation the value of freedom.”

“For me the escort to Arlington is the culmination of another year of sharing the mission to remember, honor and teach across this country. I say it every year, but it is truly an experience of a lifetime,” Karen Worcester, executive director of Wreaths Across America, said in a statement. “The way the mission and these families and veterans are welcomed into communities, with flags waving and streets lined with children and grateful Americans, is something we always wished every person could witness. This year we’re hoping that supporters will once again join us in safely lining the roadways and welcoming the escort into their communities.”

The convoy will start in Harrington, near the Worcester Wreath Co., at 7:45 a.m. with stops in Ellsworth and China before its arrival in Lewiston.

The Lewiston Police Department will join the escort when the caravan arrives along state Route 126 at the Sabattus town line between 2 and 2:30 p.m., according to Amber Caron, director of communications for Wreaths Across America.

Lewiston Police Department spokesman Lt. Derrick St. Laurent said he expects the entire caravan to consist of 50 vehicles, including the dozen tractor-trailers filled with Maine-made wreaths.

Riding in the escort vehicles will be veterans, volunteers and Gold Star Families, including Joyce Richmond of Auburn. This will be Richmond’s seventh year riding in the weeklong journey to Arlington.

“It’s hard to explain what the experience is like,” Richmond said. “It’s a very emotional week. The kids, the crowds waving flags standing along the side of the road is emotional.”

More than 150 people will be riding in the caravan.

At McMahon, Assistant Principal Michelle Russell is helping to organize the ceremony in the gymnasium. Mayor Carl Sheline and Superintendent Jake Langlois are expected to address the crowd. The Lewiston Police Honor Guard will participate, as will a bagpipe player, and a trumpeter playing taps.

Russell is hoping veterans and families will line North Temple Street to wave signs and flags to welcome the caravan. She added that firefighters are expected to hang an American flag over the entrance.

Following the ceremony, the caravan will proceed to Main Street and pass Veterans Memorial Park  before entering Auburn en route to Sunday’s final stop in Portland, which will host a parade on Congress Street beginning at 6 p.m.

The caravan will continue with several daily stops in New Hampshire, Connecticut, New Jersey, Pennsylvania, Delaware, Maryland and Washington, D.C. before arriving at Arlington National Cemetery  in Arlington, Virginia, on Saturday, Dec. 17.