Portsmouth Company
Open-knowledge reference entry

The Portsmouth Company was a cotton mill established in 1832 in South Berwick, Maine, UA, one of several in the area. It was operated for many years under the control of the Portsmouth, New Hampshire-based Hale family.
Its counting house is now a museum operated by the Old Berwick Historical Society.
History
The Portsmouth Company cotton mill was incorporated in 1831. It operated a large mill in South Berwick, Maine.
The Counting House museum
The Counting House is a historic industrial building at Main and Liberty Streets in South Berwick, the only company structure to survive. Although it is traditionally given a construction date of 1832, architectural evidence suggests a later one around 1850. It was listed on the National Register of Historic Places in 1975, and is now home to the Old Berwick Historical Society, which operates it as the Counting House Museum.
Description
The Portsmouth Company Counting House is a 2½ story brick structure set at the southern corner of Liberty Street and Main Street (Maine State Route 4), on the eastern bank of the Salmon Falls River. It sits on a granite foundation and is topped by a steeply pitched gabled roof.
The public source identifies “Portsmouth Company” as open-knowledge reference entry. This brief keeps that definition visible, then builds a research path around Portsmouth, Company and Open-knowledge.
Why this record matters
A short description can identify a subject without explaining its stakes. For “Portsmouth Company”, the useful work is to connect “open-knowledge reference entry” to the records capable of establishing context and consequence.
Named sources, stable identifiers and responsible institutions provide the strongest route from overview to verifiable evidence. The source revision retrieved here is dated Aug 31, 2026. The linked authority identifier is Q22059383. Authority coordinates are 43.227, -70.811. 1 of 1 selected statements include explicit references; 0 carry qualifiers and 0 use preferred rank. The first chronological checks are 1832, 1831, 1850 and 1975.
Overview language is designed for orientation and should not be treated as a substitute for the evidence cited beneath it. The source lead contains qualifying language; that uncertainty should survive quotation, summary and reuse. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
How to read it
Use the entry as an orientation point, then follow its citations and revision history. Names, dates and institutional relationships should be checked against the original record.
- Subject orientation
- Search vocabulary
- Locating named sources
The closest primary source, responsible institution and strongest cited specialist reference.
Three-step research path
- Establish the record: confirm the title “Portsmouth Company”, its source revision and the description used here.
- Expand the search: follow Portsmouth Company primary sources, Portsmouth Company archive and Portsmouth research across catalogues and specialist indexes.
- Test the account: compare the strongest cited source with the responsible institution’s current record and note any disagreement.
Questions for further research
- Which source most directly establishes the central claim about “Portsmouth Company”?
- Which institution is responsible for the underlying evidence?
- What terminology or title could unlock a more precise catalogue search?
Search terms from this dossier
This entry incorporates text from “Portsmouth Company” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.