About 20,000 volunteers helped place the wreaths throughout the cemetery Saturday, Stars and Stripes reported.
The tradition was started 21 years ago when a businessman -- a retired Marine -- donated a surplus of Christmas wreaths to the cemetery. Since then, the event has grown, with more wreaths being laid every year.
This year, Merrill Worcester, owner of Worcester Wreath Co. in Harrington, Maine, presented the program's 1 millionth wreath. It went to Gold Star mother Mary Byers, whose son, Army Capt. Joshua Byers, was killed in Afghanistan in 2003, the newspaper said.
Byers, who attended the event with her husband Lloyd and Army Sgt. Justin Lansford, who was severely wounded by a roadside bomb in Afghanistan in April, placed the milestone wreath on the grave of Vietnam veteran Wilbur Tresvant.