The U.S. National Park Service says a proposed 250-foot monumental arch near Memorial Circle in Washington could adversely affect views and other characteristics of dozens of historic properties, including visual connections around the Lincoln Memorial and Arlington House. The assessment was issued as part of a federal historic-preservation review of the project. The findings do not automatically block construction, but they require agencies to consider ways to avoid, reduce or mitigate the effects, including possible changes to the arch’s location or design.