{"nrhp_refnum":"73000289","name":"Old Chelmsford Garrison House Complex","other_names":["Heywood House"],"category":"building","location":{"address":"105 Garrison Rd.","address_restricted":false,"city":"Chelmsford","county":"Middlesex County","state":"MA","lat":42.57851068000008,"lon":-71.39167695399993,"geom_source":"nps_gis"},"listed_date":"1973-05-08","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Military","Architecture"],"significance_levels":["local"],"summary":{"what_it_is":"A 1.4-acre complex on Garrison Road in Chelmsford, Massachusetts, centered on a saltbox garrison house built about 1691, with a barn, a craft center and an educational building.","why_significant":"The Garrison House is described as the oldest authenticated 17th-century building in Chelmsford and the best example of the saltbox style in the town. It is the only survivor of nineteen garrison houses that once stood there. It is also tied to the Adams family, whose early members first held the land.","narrative":"Garrison Road in Chelmsford holds a 1.4-acre complex built around the town's oldest authenticated 17th-century building. The main house dates to about 1691 and was built by Pelatiah Adams on land first held by his father, Lt. Thomas Adams, a Selectman and original petitioner for the Chelmsford land grant. It began as a two-story clapboard house with a central chimney of unmortared stone. Around 1702 a rear lean-to with two borning rooms, two kitchens and a pantry gave it the saltbox profile seen today. Benjamin Heywood of Billerica bought it in 1728, and his descendants kept it until 1922. It is the only one of nineteen garrison houses once standing in Chelmsford to survive. Since 1959 an association has restored it and run it as a museum and educational center. The grounds also include a barn, a craft center converted from a henhouse in 1966, and a portable Hodgson building moved there in 1969.","period_of_significance":"17th and 18th centuries (checked on the form; no specific dates given)","architect_builder":"Built by Pelatiah Adams, son of Lt. Thomas Adams","architectural_style":"Saltbox","criteria":[],"status_note":"Condition marked good and altered; on its original site. Maintained by a private association as a museum and educational center, with a caretaker's apartment in the former slaughterhouse.","vacant_flag":false,"machine_generated":true,"model":"claude-sonnet-5-5","prompt_version":"v1.0-2026-10-29","generated_at":"2026-10-29 02:11:53.81331-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/opastorage/live/95/7959/63795995/content/electronic-records/rg-079/NPS_MA/73000289.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/73000289/78d7cb124e-800.webp","url_1600":"https://nationalhistoricalregister.com/media/73000289/78d7cb124e-1600.webp","licence":"CC BY 3.0","author":"John Phelan","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:Old_Chelmsford_Garrison_House,_MA.jpg\" rel=\"noopener\">John Phelan</a>, <a href=\"https://creativecommons.org/licenses/by/3.0\" rel=\"license noopener\">CC BY 3.0</a>, via Wikimedia Commons","source_page":"https://commons.wikimedia.org/wiki/File:Old_Chelmsford_Garrison_House,_MA.jpg"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/63795995","wikipedia":"https://en.wikipedia.org/wiki/Old_Chelmsford_Garrison_House","wikidata":"https://www.wikidata.org/wiki/Q7083645"},"indexable":true,"url":"https://nationalhistoricalregister.com/massachusetts/middlesex-county/old-chelmsford-garrison-house-complex-73000289/"}