Union Township, Clinton County

• Cowan LakeBuilt 1947 · 670 acres

How Union Township, Clinton County began

Union Township was organized in 1813, assembled out of land taken from three older townships — Chester, Richland, and Vernon — and named for that union of parcels. It sits at the geographic center of Clinton County and has always contained the county seat, Wilmington, but the township itself is the surrounding rural and semi-rural land: farms, the former Clinton County Air Force Base (later the Airborne Airpark cargo hub and now Wilmington Air Park), and Clinton Field airport in its northwestern corner. Nine other townships border it — Liberty, Wilson, Richland, Wayne, Green, Washington, Vernon, Adams, and Chester. As of the 2020 census the township held 3,140 residents outside Wilmington's own city population, at a density of about 64 people per square mile, reflecting its continued rural character even with the county seat inside its boundaries.

Incorporated 1813 (township organized), by Organized in 1813 from land combined out of Chester, Richland, and Vernon townships.

Where the name comes from

Union Township was so named because it was formed from a 'union' of land given up by three neighboring townships — Chester, Richland, and Vernon — when it was organized in 1813, rather than for any person or place.

Before the town

No specific historic Native American village, camp, or trail is recorded within Union Township's rural area outside Wilmington. The strongest documented prehistoric site near the township is the Cowan Creek Circular Enclosure, an Adena-culture earthwork with an associated mound (radiocarbon-linked burial dated to roughly AD 500) southwest of Wilmington, now within Cowan Lake State Park; more than twenty additional burial mounds once stood in the surrounding fields and are now submerged under Cowan Lake. That site lies close to Union Township's boundary near the Vernon/Adams township lines southwest of the city, but it is described only relative to Wilmington, so it is treated here as a county and Wilmington-area feature rather than placed inside Union Township. Clinton County as a whole lies south and east of the 1795 Treaty of Greenville line (which ran from Fort Recovery through Fort Laurens to the mouth of the Cuyahoga River), so the land that became Union Township was inside the territory the Treaty of Greenville ceded to the United States, opening it to the surveys and settlement that produced the township in 1813; no specific historic Shawnee, Myaamia (Miami), Wyandot, or Lenape (Delaware) settlement, trail, or leader is recorded for Union Township's own ground.

Nations recorded here: Adena culture.

Timeline

1. 1801-03 — Timothy Bennett, a veteran of Harmar's 1790 march who had lived in Kentucky, settles a mile and a half east of the site of Wilmington, one of the very earliest pioneers of the county.
2. 1803 — George Haworth, a Quaker minister from Tennessee, settles on Todd's Fork on 1,750 acres, the second settler in the township, and builds a gristmill.
3. 1805 — Robert Eachus builds a gristmill on Todd's Fork, probably the first in the county, and in May a Friends meeting house of unhewn logs is organized at his home, probably the first house of worship in Clinton County.
4. c. 1806 — Mahlon Haworth builds a gristmill on Todd's Fork run by horse and water power.
5. 1810 — Clinton County is formed (effective March 1, 1810) from parts of Highland and Warren counties; the land that becomes Union Township is inside the new county from its creation.
6. 1810 — Nathan Linton, who had surveyed between the Miami and Scioto rivers from 1803, is appointed first county surveyor and serves twenty years.
7. c. 1812 — William Butler erects a saw and gristmill on Lytle's Creek a mile from Wilmington; Nathan Stalker builds another in 1815.
8. 1813 — Union Township is organized, formed by combining land taken from Chester, Richland, and Vernon townships.
9. 1880 — The 1880 census counts 2,306 residents in Union Township outside Wilmington's 2,745.
10. 1915 — The township outside Wilmington has about 1,226 residents.
11. 1971 — Clinton County Air Force Base, which sits on township land outside the city, closes; Wikipedia says the economy of the city of Wilmington then hovered in recession for more than a decade.
12. 1978-2009 — The former Air Force base becomes the Airborne Airpark, later DHL's Wilmington Air Park cargo hub, one of the country's larger overnight-freight operations until DHL's 2009 closure; the airpark and its rural surroundings sit within Union Township, distinct from the city of Wilmington itself.
13. 2020 — The U.S. Census records Union Township's population at 3,140, at a density of about 63.9 people per square mile across its 49.2 square miles of land.

Stories

A township stitched together from three neighbors

When Clinton County's early townships were still being sorted out, the land that would hold the new county seat did not belong to any single existing township — it sat at the meeting point of Chester, Richland, and Vernon. In 1813, three years after the county itself was formed, local organizers carved pieces from all three and joined them into one new township, naming it Union for the joining itself rather than for any founder or landmark. That practical, almost administrative origin — a township assembled to give the county seat a home township of its own — set Union Township apart from neighbors named for places, presidents, or settlers. It has held the county's largest population center, Wilmington, at its heart ever since, while the township's own rural fringe kept its own separate identity as farmland surrounding the city.

A military base becomes the township's second identity

Outside Wilmington's city limits, in the township's countryside, the U.S. Air Force built Clinton County Air Force Base and ran it through the Cold War before closing it in 1971. Rather than stand empty, the base found a second life as a civilian air-freight hub in 1978, growing over three decades into the Airborne Airpark and then DHL's Wilmington Air Park — at its peak one of the largest overnight cargo operations in the country, employing thousands of area residents. Because the airpark sits on township land rather than inside the city, its rise and its abrupt 2009 collapse (when DHL pulled out and roughly 8,000 jobs disappeared) were as much a Union Township story as a Wilmington one, reshaping the rural land around the county seat twice in one lifetime.

Local history sources: en.wikipedia.org · en.wikipedia.org · en.wikipedia.org · en.wikipedia.org · en.wikipedia.org · en.wikipedia.org · en.wikipedia.org · en.wikipedia.org · en.wikipedia.org · archive.org · archive.org · archive.org

Caesar Creek Lake (about 14 miles northwest of Wilmington) is a source, treated at a surface-water lime-softening plant. Two reservoirs near Burtonville, about 3 miles south of Wilmington, are kept as an alternative source and can be filled from Cowan Creek OR Caesar Creek Lake; often used when Caesar Creek Lake water is poor quality. There is also an auxiliary connection to Western Water Company for outlying customers during main-break repairs. The water here

• Wilmington City76% of residentsCaesar Creek Lake (with Burtonville reservoirs/Cowan Creek as backup)
• Western Water Company24% of residentsLittle Miami River valley wells (51%) plus Cincinnati Ohio River water (49%)

High-hazard dams (1)

Public schools (1)

Superfund sites (1)

Facilities reporting toxic releases (2)

Spills reported since 2021 (5)

Elections for office

Winners in bold. Results from the county board of elections' official canvass unless marked. The county's results on file run through 2026-05-05; later elections are not loaded yet.

Auditor of State record

• No fiscal caution, watch or emergency on the Auditor of State's lists.
• Agreed Upon Procedures, 2023 to 2024, released 2025-08-19

Statewide question: State Issue 3: Voter ID

Local questions for Union Township, Clinton County, Clinton County and its school district:

• Clinton County: Miscellaneous, for Gas aggregation.
• Clinton County: Renews a 0.5-mill property tax levy to maintain & operate health department of Clinton County for 5 years, beginning in 2027.
• Clinton County: Renews a 2.35-mill property tax levy for the provide & maintain senior citizens services or facilities of Clinton County for 5 years, beginning in 2027.

Races, candidates and every question for an address: your ballot. County offices and judges are on your county board's sample ballot.

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