The National Park Service has found that 37 historic places would be damaged by a proposed 250-foot arch at Memorial Circle, the traffic circle below Arlington National Cemetery near the National Mall, according to NPR.

President Trump proposed the arch, formally called the United States Triumphal Arch, to honor the nation's 250th anniversary. The NPS is designing the project and has listed it on its ParkPlanning website. If built, the arch would change the view across Washington and Arlington Cemetery, as The New York Times reported on August 3.

The findings came from a review required by a federal law called the National Historic Preservation Act. That law says government agencies must check whether their projects would harm historic places and must try to reduce that harm. The NPS wrote two reports for this project.

One report looked at the environment in general and found the project would not cause major environmental damage. The other report focused on historic sites and reached a different conclusion. It found that an arch at Memorial Circle would interfere with dozens of historic places — especially the view between the Lincoln Memorial and Arlington House, the former home of Confederate Gen. Robert E. Lee.

The White House has defended the location. A White House statement called Memorial Circle an ideal spot, saying the arch would be a "fitting addition to the monumental axis between the Lincoln Memorial and Arlington House" and would improve the visitor experience at Arlington National Cemetery. That statement speaks to the same historic view that the NPS report identified as the most at risk.

A group of Vietnam War veterans has sued to stop construction. They argue the arch would ruin the view and that Congress would need to approve it first. The lawsuit adds a legal challenge on top of the ongoing government review process.

Preservationists say the finding of 37 affected sites shows the location needs more scrutiny. They point out that other places in Washington could hold an arch this size with far fewer effects on historic properties. The NPS report does not look at other sites; it only studies what would happen at Memorial Circle.

The two reports reached different conclusions because they follow different laws. Think of it like a building inspection: one inspector checks the plumbing and says it is fine, while another inspector checks the electrical system and finds serious problems. Both inspections are real, but they look at different things. In this case, the environmental review passed, but the historic-preservation review found problems that still need to be resolved through consultation with preservation officials and other groups.

The view between the Lincoln Memorial and Arlington House is one of the most protected sights in Washington. It was designed more than a century ago as part of a city plan that shaped the capital's major landmarks. Memorial Circle sits at the narrowest point of that view, which is why the NPS report focused its warning there.

The 250th anniversary timeline adds pressure. Commemorations are already underway across federal agencies, and a monument meant for the anniversary would still need to clear the historic-preservation review, the veterans' lawsuit, and questions about whether Congress needs to authorize it. The NPS has not announced a construction timeline.