Dear Ms. Enderle,
Thank you for posting your question on History Hub!
A search of The National Archives Catalog returns a result from our National Park Service holdings. There are some documents pertaining to Philipsburg Manor and its designation on the National Register of Historic Places. You can view the catalog entry here: https://catalog.archives.gov/id/75316126
These records are located at The National Archives at College Park, Electronic Records Division. For reference on these records you may contact them via: firstname.lastname@example.org
Due to the COVID-19 pandemic and pursuant to guidance received from the Office of Management and Budget (OMB), NARA has adjusted its normal operations to balance the need of completing its mission-critical work while also adhering to the recommended social distancing for the safety of NARA staff. As a result of this re-prioritization of activities, you may experience a delay in receiving an initial acknowledgement as well as a substantive response to your reference request from National Archives at Washington, DC - Textual Reference (RDT1). We apologize for this inconvenience and appreciate your understanding and patience.