Renames the existing Salem maritime unit in the National Park System from a "National Historic Site" to a "National Historical Park," and treats all existing references to the old name as referring to the new name. Directs the Secretary of the Interior to conduct a boundary study to evaluate whether additional sites in and around Salem, Massachusetts, that reflect maritime history, coastal defenses, and military/National Guard and militia activity should be added to the park; the Secretary must report the study’s findings and recommendations to two congressional committees within three years after funding is available.