Americans are honoring the nation's military war dead on this Memorial Day holiday in the United States.
President Bush led observances at Arlington National Cemetery.
This is the day when America remembers those who died in service to their country. And nowhere is the extent of their sacrifice more on display than in Arlington National Cemetery - where seven generations of the fallen are buried.
"Today, we honor the warriors who fought our nation's enemies, defended the cause of liberty and gave their lives in the cause of freedom."
President Bush spoke in the cemetery's amphitheater - a massive white structure surrounded by seemingly endless rows of small white headstones. Many of the nation's greatest military heroes are buried in Arlington.
But so too are hundreds of thousands of men and women whose names are known only to the families and communities that mourn them.
They include several-hundred soldiers killed since the September 11th attacks on the United States in places like Kabul and Kandahar, Baghdad and Ramadi.
The sod is still fresh on those graves, many covered with personal messages, flowers and flags.
"Like those who came before them, they did not want war, but they answered the call when it came. They believed in something larger than themselves. They fought for our country, and our country unites to mourn them as one."
The president said their sacrifice must not be in vain, and the cause of protecting freedom will never end.
"From their deaths must come a world where the cruel dreams of tyrants and terrorists are frustrated and foiled, where our nation is more secure from attack and where the gift of liberty is secured for millions who have never known it."
Earlier, the president laid a wreath at the Tomb of the Unknowns - which contains the unidentified remains of members of the U.S. military killed in major conflicts. He was accompanied by several families of the fallen.