The National Historic Preservation Act (NHPA) is a federal law in the United States that aims to preserve historic and cultural resources, including buildings, districts, and archaeological sites. This law requires federal agencies to identify and evaluate potential impacts on historic properties during their planning and decision-making processes. Additionally, the law established the National Register of Historic Places, which provides recognition and protection for significant historic sites. Those who are knowledgeable in the NHPA have a specialized skillset and are often involved in historic preservation and restoration projects.