The World War I memorial in Bladensburg, Md., shown in 2012. (Mark Gail for The Washington Post)

Supporters of a towering cross-shaped memorial at a busy intersection in Maryland asked the Supreme Court on Monday to prevent the monument from being moved or destroyed.

The American Legion wants the high court to reverse an appeals court’s ruling that said the monument, on public land and maintained with taxpayer money, is unconstitutional because it “excessively entangles the government in religion.”

The Supreme Court has not given clear guidance when it comes to displays of religion on public sites, allowing some monuments with religious content to stand while rejecting others.

At issue in Prince George’s County is a 40-foot-tall cross built in 1925 to honor local men who died in World War I. The marble-and-cement monument was funded by local families and the American Legion but is now owned by a state agency, the Maryland-National Capital Park and Planning Commission.

“The Supreme Court is the last hope for preserving the Bladensburg WWI Veterans Memorial” recognizing 49 soldiers, said a statement from Kelly Shackelford, president of First Liberty, an organization representing the American Legion and defending the monument. “We cannot allow their memory to be bulldozed.”

The legal challenge to the 93-year-old memorial began with the American Humanist Association, a Washington-based group that represents atheists and others. The group said a giant cross on government property sends a message of exclusion in violation of the First Amendment.

In 2015, a District Court judge in Maryland said the government agency had a nonreligious reason for maintaining a historically significant, secular war memorial. The Park and Planning Commission has spent about $117,000 to maintain and repair the cross, in addition to setting aside $100,000 for renovations.

The U.S. Court of Appeals for the 4th Circuit disagreed, finding that the monument’s “sectarian elements easily overwhelm the secular ones,” in part because of its size and prominent location.

Two judges suggested at oral argument the parties could resolve the lawsuit by moving the cross, changing who owns the land — or even removing the cross’s arms.

The appeals court refused in March to rehear the case with a full panel of judges. The divided decision not to review the case included passionate dissents from several judges who said allowing the ruling to stand would threaten other monuments throughout the country, including at Arlington National Cemetery.

Maryland Gov. Larry Hogan (R) has called the court’s ruling “an affront to all veterans.”

The Park and Planning Commission plans to file its petition by Friday and is represented by Neal Katyal, a former acting solicitor general who argued against President Trump’s travel ban.

The American Humanist Association will have 30 days to respond. The high court is not expected to decide whether to take the case until after its summer recess.