Most of Unionville was built recently: 5% of its homes predate 1940 and the median home dates from 1986. Below: maps from 1909 on and old-book passages.
Every edition of the U.S. Geological Survey’s map of Unionville. Tap a year, or press play to watch the town change.
1909Butler sheet · 1:62,500
U.S. Geological Survey historical topographic maps (public domain), via Esri’s collection of the scans. The red ring marks the center of Unionville.
The story so far
Unionville, in brief
Wikipedia doesn’t have a history of Unionville yet. The photos, dates and memories neighbors add here are how it gets written.
Unionville is a census-designated place located in Center Township, Butler County, in the U.S. state of Pennsylvania. As of the 2010 census, the population was 962. Unionville is located in the northwestern corner of Center Township and is bordered to the southwest by the Shanor-Northvue CDP, to the north by Clay Township and to the west by Franklin Township. Pennsylvania Route 8 passes through the community, leading south 6 miles (10 km) to Butler, the county seat, and north 14 miles (23 km) to Harrisville.
Between the 2010 and 2020 censuses its population fell from 962 to 849 (-12%).
Intro from Wikipedia. Population: U.S. Census Bureau.
From the old history books
What they wrote about Unionville, 1883–1927
Passages that mention Unionville, cut from the printed page as they were published.
Unionville was founded by Samuel Thompson, at a point on the Mercer turnpike, seven miles northwest of Butler boroughin 1828. On December 31 of that year, a sale of lots took place, and two or three small buildings were erected near Thompson's store. James Thompson succeeded Samuel as merchant in 1830 ; but in 1833 or 1834, Samuel resumed his mercantile character. David Stewart, the owner of the tavern and first postmaster, succeeded the Thompsons as merchant, while Blaisdell & Cornish established an opposition store. One or two others engaged in business here before David and Mark McCandless began mer-
Text read by machine from the scan; it may contain errors.
History of Butler County, Pennsylvania.1895 · page 791Read the page →
Read the text
four years, and later was connected lor two years with a branch ol the same firm at Xevv Orleans. On his return from the South, he opened a general store at Wurtemburg, Beaver county, which he carried on for a short period. In June, 1847, he located at Unionville, Butler county, opened the first general store in that village, and conducted it successfully forty-four years. He was also extensively engaged in farming and was postmaster of Unionville for many years. Mr.
Text read by machine from the scan; it may contain errors.
History of Butler County, Pennsylvania. With illustrations and biographical sketches of some of its prominent men and pioneers1883Read the page →
Read the text
J. Whittaker, going to that city in 1839. He then returned to his father's house near Unionville and engaged in practice, and some ten years later moved to his residence in Unionville (a view of which can be found on another page), where he remained until his demise, January 5, 1875. As a physician, he was a model of professional honesty, candor and faithfulness.
Text read by machine from the scan; it may contain errors.
History of Butler County Pennsylvania1927 · page 506Read the page →
Read the text
Unionville, a village in the northwest corner of this township, was founded by Samuel Thompson in 1828. He was the first merchant of the place.
Text read by machine from the scan; it may contain errors.
Scans and text from the Internet Archive. Books published in 1930 or earlier, which are in the public domain.
By decade
No old photos in the archives yet
Weddings on Main Street, storms, parades, school pictures, the old store. If it’s in your family album, it belongs here.
Be the first to add onePhotograph a print flat, in daylight, no flash.
Founding dates: Wikidata, Wikipedia, the U.S. post office records of Blevins & Helbock (CC0) and the Census. Homes by year built: Census ACS 2020–24. National Register of Historic Places: National Park Service (list of May 22, 2026). Old photos, postcards and papers: Wikimedia Commons, the Library of Congress and other public archives, credited on each item’s page. Maps: U.S. Geological Survey historical topographic maps (via Esri) and Sanborn fire-insurance maps (Library of Congress). History text and census tables: Wikipedia (CC BY-SA 4.0). Places that used to be: USGS Geographic Names Information System (2021). How TownRatings grades history →
From Wikidata and Wikipedia for famous people, U.S. Geological Survey historical maps and old county and town histories (Internet Archive). Archive images are copied here with their credits and licenses, shown on each photo’s page. Refreshed monthly.
