Rochester, Illinois
village in Sangamon County, Illinois, United States
Rochester is a village and suburb of Springfield in Sangamon County, Illinois, United States. As of the 2020 census, Rochester had a population of 3,863. The village was settled in 1819, and is located in Rochester Township.
Rochester is part of the Springfield, Illinois Metropolitan Statistical Area.
Geography
Rochester is located four miles (6.4 km) outside Springfield, Illinois, down Illinois State Route 29. The village is exit 96A off Interstate 55.
According to the 2010 census, Rochester has a total area of 2.431 square miles (6.30 km2), of which 2.43 square miles (6.29 km2) (or 99.96%) is land and 0.001 square miles (0.00 km2) (or 0.04%) is water.
Demographics
2020 census
As of the 2020 census, Rochester had a population of 3,863. The median age was 41.1 years. 26.2% of residents were under the age of 18 and 18.9% of residents were 65 years of age or older.
This brief starts where responsible research should: with the source description of “Rochester, Illinois” as village in Sangamon County, Illinois, United States. Everything that follows is an evidence route, not borrowed authority.
Why this record matters
The subject matters to the places & architecture register because the source frames it as village in Sangamon County, Illinois, United States. Its deeper value depends on whether names, dates, institutions and citations support that framing.
Maps, plans, fabric surveys and administrative records can establish how the site’s name, extent and function changed over time. The source revision retrieved here is dated Sep 14, 2026. The linked authority identifier is Q2514320. VIAF identifies the subject as 133861899. The Library of Congress control number is n96102653. Authority coordinates are 39.751, -89.542. 4 of 5 selected statements include explicit references; 0 carry qualifiers and 0 use preferred rank. The first chronological checks are 2020, 1819 and 2010.
A single description cannot reconcile every naming convention, rebuilding phase or administrative transfer associated with a place. 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.
- Historic place names
- Jurisdictional context
- Routes into maps and plans
Contemporary maps, plans, listed-building records, estate papers and the responsible local or national archive.
Three-step research path
- Establish the record: confirm the title “Rochester, Illinois”, its source revision and the description used here.
- Expand the search: follow Rochester, Illinois primary sources, Rochester, Illinois archive and Rochester 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 “Rochester, Illinois”?
- What physical evidence or contemporary plan supports the description?
- Which authority defined the place, boundary or structure at the relevant date?
Search terms from this dossier
This entry incorporates text from “Rochester, Illinois” 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.