Story highlights The defendants argued that the cross had a nonreligious purpose

They plan to appeal case to the Supreme Court

Washington (CNN) A federal appeals court has ruled that a 40-foot cross-shaped Maryland monument honoring soldiers who died in World War I is unconstitutional, saying it violates the separation between church and state.

The 4th US Circuit Court of Appeals ruled Wednesday that the 92-year-old structure was in violation of the First Amendment because it is on public land at a busy intersection in Prince George's County and is maintained with government funds. The court's decision does not address whether the monument should be removed or modified.

The defendants -- the Maryland-National Capital Park and Planning Commission and the American Legion -- argued that the cross had a nonreligious purpose and "does not have the primary effect of endorsing religion," according to the majority opinion written by Judges Stephanie Thacker and James Wynn.

But the appeals court in Richmond, Virginia, sided 2-1 with the American Humanist Association, an organization that advocates for secularism and represented several non-Christian residents of Prince George's County.

Thacker and Wynn wrote that the memorial "excessively entangles the government in religion" and "breaches the wall of separation between Church and State."

Read More