Jefferson County, Pennsylvania
county in Pennsylvania, United States
Jefferson County is a county in the Commonwealth of Pennsylvania. As of the 2020 census, the population was 44,492. Its county seat is Brookville. The county was established on March 26, 1804, from part of Lycoming County and later organized in 1830. It is named after President Thomas Jefferson. It is home to Punxsutawney Phil, the most famous groundhog that predicts when spring will come every February 2 on Groundhog Day. The county is part of the North Central region of the commonwealth.
Geography
According to the U.S. Census Bureau, the county has a total area of 657 square miles (1,700 km2), of which 652 square miles (1,690 km2) is land and 4.4 square miles (11 km2) (0.7%) is water. It has a warm-summer humid continental climate (Dfb) and average monthly temperatures in Brookville range from 24.8 °F in January to 68.8 °F in July, while in Punxsutawney they range from 25.7 °F in January to 69.6 °F in July. Jefferson County is one of the 423 counties served by the Appalachian Regional Commission, and it is identified as part of the "Midlands" by Colin Woodard in his book American Nations: A History of the Eleven Rival Regional Cultures of North America.
“Jefferson County, Pennsylvania” enters the record as county in Pennsylvania, United States. Crown Archives preserves that source wording while asking what Jefferson, County and Pennsylvania can confirm, complicate or overturn.
Why this record matters
“Jefferson County, Pennsylvania” is worth following because a concise public description often conceals a longer documentary argument. Here, Jefferson, County and Pennsylvania provides the most credible route into that argument.
The strongest evidence will usually combine a dated visual record with documents produced by the authority responsible for the place. The source revision retrieved here is dated Sep 20, 2026. The linked authority identifier is Q494156. VIAF identifies the subject as 146581207. The Library of Congress control number is n80107107. Authority coordinates are 41.130, -79.000. 5 of 5 selected statements include explicit references; 0 carry qualifiers and 0 use preferred rank. The first chronological checks are 2020, 1804 and 1830.
Architectural summaries often privilege surviving fabric and can understate demolished phases, contested use or displaced communities. The lead is largely declarative, so disagreement and counter-evidence require a deliberate search beyond the opening account. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
How to read it
Treat names, boundaries and functions as historically changeable. Maps, plans, inventories and administrative records can clarify what the place meant at different dates.
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Contemporary maps, plans, listed-building records, estate papers and the responsible local or national archive.
Three-step research path
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Questions for further research
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This entry incorporates text from “Jefferson County, Pennsylvania” 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.