A Maryland district court has upheld the constitutionality of a veterans' memorial monument in Bladensburg, junking the lawsuit filed by an atheist group that claimed it violated the Establishment Clause.

The American Humanist Association (AHA) filed the lawsuit last February against the Maryland National Capital Park and Planning Commission as it sought the removal of the historic Bladensburg World War I Veterans Memorial that was built in 1925.

"It is hereby declared that the ownership, maintenance and display of the Monument by the Commission do not violate the Establishment Clause of the First Amendment to the United States Constitution," District Judge Deborah Chasanow ruled on Monday.

"When the government erects an exclusively Christian monument on government property, it violates this central command of the Establishment Clause by sending a clear message that Christianity is the preferred religion over all others. When the religious monument is dedicated to fallen soldiers, it sends an even more egregious message that only Christian soldiers are worth memorialising," wrote AHA lawyer Monica Miller on the association's website last year.

The Liberty Institute and Jones Day intervened in the lawsuit on behalf of the American Legion.

The monument is a tribute to the 49 men of Prince George's County who gave their lives during the First World War, the institute said.

It is located at the Veterans Memorial Park in the immediate vicinity of memorials to those who served in the War of 1812, World War II, the Korean War, and the Vietnam War, and a memorial to the fallen of the Sept. 11, 2001 attacks.

The base of the Memorial Cross features a bronze plaque that lists the names of the 49 fallen soldiers. A plaque above the names reads, "This Memorial Cross Dedicated To The Heroes of Prince George's County Who Gave Their Lives In The Great War For The Liberty Of The World."

There is also a quote from President Woodrow Wilson, which says, "The right is more precious than peace; we shall fight for the things we have always carried nearest to our hearts; to such a task we dedicate our lives."

The words "Valor," "Endurance," "Courage" and Devotion" are inscribed on the base of the memorial.

"We are grateful that the Court ruled in our favour and upheld the memorial's lawfulness under the First Amendment. This memorial has stood for almost 100 years in honour of the fallen and should be allowed to stand for 100 more," said Noel Francisco, lead counsel for the American Legion and chair of Jones Day's Government Regulation Practice.