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County · code 47173

Union CountyTennessee

Union County is a county in Tennessee with its seat in Maynardville. It was created on January 26, 1854, from Anderson, Campbell, Claiborne, Grainger, and Knox counties.

  • Founded1854
  • County seatMaynardville
  • Land area224 sq mi + 24 sq mi water
  • Population19,802 2020 Census
  • Parcels mapped14,722 checked 14 October 2026
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Updated

ClaiborneKnoxGraingerCampbellAnderson Maynardville Census outline · seat marked

Where it is

Union on the map of Tennessee

Tennessee has 95 counties and county equivalents, each with its own records office. Shapes with a page are links.

Anderson CountyBedford CountyBenton CountyBledsoe CountyBlount CountyBradley CountyCampbell CountyCannon CountyCarroll CountyCarter CountyCheatham CountyChester CountyClaiborne CountyClay CountyCocke CountyCoffee CountyCrockett CountyCumberland CountyDavidson CountyDecatur CountyDeKalb CountyDickson CountyDyer CountyFayette CountyFentress CountyFranklin CountyGibson CountyGiles CountyGrainger CountyGreene CountyGrundy CountyHamblen CountyHamilton CountyHancock CountyHardeman CountyHardin CountyHawkins CountyHaywood CountyHenderson CountyHenry CountyHickman CountyHouston CountyHumphreys CountyJackson CountyJefferson CountyJohnson CountyKnox CountyLake CountyLauderdale CountyLawrence CountyLewis CountyLincoln CountyLoudon CountyMcMinn CountyMcNairy CountyMacon CountyMadison CountyMarion CountyMarshall CountyMaury CountyMeigs CountyMonroe CountyMontgomery CountyMoore CountyMorgan CountyObion CountyOverton CountyPerry CountyPickett CountyPolk CountyPutnam CountyRhea CountyRoane CountyRobertson CountyRutherford CountyScott CountySequatchie CountySevier CountyShelby CountySmith CountyStewart CountySullivan CountySumner CountyTipton CountyTrousdale CountyUnicoi CountyVan Buren CountyWarren CountyWashington CountyWayne CountyWeakley CountyWhite CountyWilliamson CountyWilson CountyUnion County Union
Counties of Tennessee · Union highlighted

History

Formed in 1854 from Anderson County, Campbell County, Claiborne County, Grainger County and Knox County

An old deed may name a county that no longer exists, or a boundary that has since moved.

Union County underwent multiple boundary adjustments in its early decades, exchanging and gaining territory with neighboring counties including Knox, Claiborne, Campbell, and Grainger through the 1870s.

Boundary changes from the Newberry Library, Atlas of Historical County Boundaries; the 5 that matter most are shown first.

  1. 1854
    Union County created Union created from Anderson, Campbell, Claiborne, Grainger, and Knox.
    from Andersonfrom Campbellfrom Claibornefrom Graingerfrom Knox
    · Tenn. Acts 1849, 28th assy., ch. 61, secs. 1-2, 4, 18/pp. 181-187; Tenn. Acts 1851, 29th assy., ch. 22/p. 26; Tenn. Acts 1853, 30th assy., ch. 2, secs. 1-2/pp. 25-26; Graves, 1:68-69
  2. 1856
    Exchanged territory Union exchanged with Knox.
    with Knox
    · Tenn. Acts 1855, 31st assy., ch. 165/p. 256
  3. 1866
    Gained territory Union gained from Knox.
    from Knox
    · Tenn. Acts 1865, 34th assy., 2d sess., priv., ch. 76/p. 224
  4. 1870
    Gained territory Union gained from Claiborne to accommodate local residents.
    from Claiborne
    · Tenn. Acts 1869, 36th assy., 1st sess., pub., ch. 88/p. 105
  5. 1982
    Gained territory Union gained from Knox to accommodate local resident.
    from Knox
    · Tenn. Acts 1982, 92d assy., 2d reg. sess., pub., ch. 666/p. 202
Show all 44 changes (39 more, mostly small adjustments)
  1. 1854
    Union County created Union created from Anderson, Campbell, Claiborne, Grainger, and Knox.
    from Andersonfrom Campbellfrom Claibornefrom Graingerfrom Knox
    · Tenn. Acts 1849, 28th assy., ch. 61, secs. 1-2, 4, 18/pp. 181-187; Tenn. Acts 1851, 29th assy., ch. 22/p. 26; Tenn. Acts 1853, 30th assy., ch. 2, secs. 1-2/pp. 25-26; Graves, 1:68-69
  2. 1856
    Exchanged territory Union exchanged with Knox.
    with Knox
    · Tenn. Acts 1855, 31st assy., ch. 165/p. 256
  3. 1856
    Lost territory Union lost to Claiborne to accommodate local resident (later repealed).
    to Claiborne
    · Tenn. Acts 1855, 31st assy., ch. 166 [printed as 156]/p. 258
  4. 1860
    Gained territory Union gained from Campbell, Claiborne, and Knox to accommodate local residents (later repealed); Union lost small area to Campbell.
    from Campbellfrom Claibornefrom Knox
    · Tenn. Acts 1859, 33d assy., 1st sess., priv., ch. 196, secs. 1-11/pp. 575-577
  5. 1866
    Gained territory Union gained from Knox.
    from Knox
    · Tenn. Acts 1865, 34th assy., 2d sess., priv., ch. 76/p. 224
  6. 1868
    Gained territory Union gained from Claiborne to accommodate local resident.
    from Claiborne
    · Tenn. Acts 1867, 35th assy., 1st sess., pub., ch. 60/p. 75
  7. 1870
    Gained territory Union gained from Claiborne to accommodate local residents.
    from Claiborne
    · Tenn. Acts 1869, 36th assy., 1st sess., pub., ch. 88/p. 105
  8. 1871
    Gained territory Union gained from Grainger to accommodate local residents.
    from Grainger
    · Tenn. Acts 1870, 36th assy., 3d sess., ch. 118/p. 136
  9. 1871
    Gained territory Union gained from Campbell to accommodate local residents.
    from Campbell
    · Tenn. Acts 1871, 37th assy., 1st sess., ch. 7/p. 7
  10. 1873
    Gained territory Union gained from Grainger to accommodate local residents; Union lost to Knox to accommodate local resident. Legislature authorized creation of Webster from Union, Campbell, and Claiborne; creation did not take effect.
    from Graingerfrom Knoxfrom Websterfrom Campbellfrom Claiborne
    · Tenn. Acts 1873, 38th assy., ch. 70/p. 104; ch. 72/p. 106; ch. 77, secs. 1, 13/pp. 111, 115; McBride, 8
  11. 1875
    Gained territory Union gained from Knox to accommodate local residents.
    from Knox
    · Tenn. Acts 1875, 39th assy., ch. 140, secs. 1-5/pp. 228-230
  12. 1879
    Lost territory Union lost to Claiborne to accommodate local resident.
    to Claiborne
    · Tenn. Acts 1879, 41st assy., 1st sess., ch. 111/p. 148
  13. 1879
    Lost territory Union lost to Claiborne to accommodate local residents.
    to Claiborne
    · Tenn. Acts 1879, 41st assy., 1st sess., ch. 137, secs. 1-17/pp. 174-177
  14. 1883
    Lost territory Union lost to Claiborne to accommodate local residents.
    to Claiborne
    · Tenn. Acts 1883, 43d assy., ch. 40/p. 46
  15. 1883
    Gained territory Union gained from Knox to accommodate local resident.
    from Knox
    · Tenn. Acts 1883, 43d assy., ch. 103/p. 100
  16. 1883
    Gained territory Union gained from Grainger (later repealed).
    from Grainger
    · Tenn. Acts 1883, 43d assy., ch. 129/p. 176
  17. 1887
    Gained territory Union gained from Knox to accommodate local resident; Union lost to Grainger to accommodate local resident (later repealed).
    from Knoxfrom Grainger
    · Tenn. Acts 1887, 45th assy., ch. 47/p. 119; ch. 49/p. 120
  18. 1887
    Gained territory Union gained from Claiborne to accommodate local residents.
    from Claiborne
    · Tenn. Acts 1887, 45th assy., ch. 227/p. 388
  19. 1887
    Lost territory Union lost to Claiborne to accommodate local resident.
    to Claiborne
    · Tenn. Acts 1887, 45th assy., ch. 45/p. 117
  20. 1889
    Lost territory Union lost to Grainger to accommodate local residents.
    to Grainger
    · Tenn. Acts 1889, 46th assy., 1st sess., ch. 24/p. 32
  21. 1889
    Lost territory Union lost to Knox to accommodate local resident.
    to Knox
    · Tenn. Acts 1889, 46th assy., 1st sess., ch. 20/p. 28
  22. 1889
    Lost territory Union lost to Knox to accommodate local residents (later overturned).
    to Knox
    · Tenn. Acts 1889, 46th assy., 1st sess., ch. 194/p. 384
  23. 1890
    Lost territory Union lost to Grainger (later repealed).
    to Grainger
    · Tenn. Acts 1890, 46th assy., 3d sess., ch. 5/p. 25
  24. 1891
    Exchanged territory Union exchanged with Claiborne to accommodate local residents.
    with Claiborne
    · Tenn. Acts 1891, 47th assy., ch. 255/p. 489
  25. 1891
    Gained territory Union gained from Claiborne to accommodate local residents.
    from Claiborne
    · Tenn. Acts 1891, 47th assy., ch. 53/p. 136
  26. 1891
    Gained territory Union gained from Knox when Tennessee Supreme Court overturned act of 4 April 1889.
    from Knox
    · "Union County v. Knox County" in Tenn. Rpts., 90:541-545
  27. 1895
    Exchanged territory Union exchanged with Claiborne to accommodate local residents.
    with Claiborne
    · Tenn. Acts 1895, 49th assy., ch. 7/p. 12
  28. 1895
    Gained territory Union gained from Grainger to accommodate local resident.
    from Grainger
    · Tenn. Acts 1895, 49th assy., ch. 104/p. 170
  29. 1895
    Gained territory Union gained from Grainger to accommodate local resident (later repealed); Union gained from Knox to accommodate local resident.
    from Graingerfrom Knox
    · Tenn. Acts 1895, 49th assy., ch. 188/p. 385; ch. 183/p. 382
  30. 1895
    Exchanged territory Union exchanged with Claiborne to accommodate local residents.
    with Claiborne
    · Tenn. Acts 1895, 49th assy., ch. 215/p. 438
  31. 1899
    Gained territory Union gained from Grainger to accommodate local residents (later repealed).
    from Grainger
    · Tenn. Acts 1899, 51st assy., ch. 233/p. 506
  32. 1901
    Lost territory Union lost to Grainger to accommodate local residents (later repealed).
    to Grainger
    · Tenn. Acts 1901, 52d assy., ch. 310/p. 697
  33. 1901
    Lost territory Union lost to Grainger to accommodate local resident (later repealed).
    to Grainger
    · Tenn. Acts 1901, 52d assy., ch. 361/p. 829
  34. 1903
    Lost territory Union lost to Campbell to accommodate local resident.
    to Campbell
    · Tenn. Acts 1903, 53d assy., ch. 386/p. 1127
  35. 1905
    Gained territory Union gained from Knox to accommodate local residents.
    from Knox
    · Tenn. Acts 1905, 54th assy., ch. 186/p. 390
  36. 1909
    Gained territory Union gained from Knox to accommodate local resident.
    from Knox
    · Tenn. Acts 1909, 56th assy., ch. 68/p. 203
  37. 1909
    Gained territory Union gained from Claiborne to accommodate local resident.
    from Claiborne
    · Tenn. Acts 1909, 56th assy., ch. 394/p. 1387
  38. 1925
    Lost territory Union lost small area to Knox.
    to Knox
    · Tenn. Acts 1925, 64th assy., priv., ch. 462/p. 1733
  39. 1937
    Gained territory Union gained from Claiborne to accommodate local resident.
    from Claiborne
    · Tenn. Acts 1937, 70th assy., priv., ch. 175/p. 509
  40. 1947
    Gained territory Union gained from Claiborne to accommodate local resident.
    from Claiborne
    · Tenn. Acts 1947, 75th assy., priv., ch. 441/p. 1765
  41. 1951
    Gained territory Union gained from Claiborne to accommodate local residents.
    from Claiborne
    · Tenn. Acts 1951, 77th assy., priv., ch. 52/p. 145
  42. 1963
    Gained territory Union gained from Knox to accommodate local resident.
    from Knox
    · Tenn. Acts 1963, 83d assy., priv., ch. 120/p. 388
  43. 1965
    Gained territory Union gained from Claiborne to accommodate local resident.
    from Claibornefrom Union-Claiborne
    · Tenn. Acts 1965, 84th assy., priv., ch. 156/p. 544
  44. 1982
    Gained territory Union gained from Knox to accommodate local resident.
    from Knox
    · Tenn. Acts 1982, 92d assy., 2d reg. sess., pub., ch. 666/p. 202

Land and parcels

What the maps cover in Union

Who publishes each layer, how good it is, and when we last checked.

Official
from the office that keeps the record
Good enough
a reliable statewide or national copy
Fallback
a guide only; check the official record
Missing
nothing public found yet

People and land

Union by the Census

Population
19,802 2020 Census count
Housing units
9,569 2020 Census count
Land area
224 square miles
Water area
24 square miles
People per sq mi
89 population ÷ land area

Source: US Census Bureau, 2020 Census; US Census Bureau, 2020 Gazetteer Files. Not endorsed or certified by the Census Bureau.

Rules and offices

Union County's official site

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County government

See your own lot on these maps

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Questions

Common questions about Union County

When was Union County founded?
Union County was founded in 1854, formed from Anderson County, Campbell County, Claiborne County, Grainger County and Knox County.
What is the county seat of Union County?
The county seat of Union County is Maynardville.
Is there an online parcel map for Union County?
Yes. Tennessee Comptroller of the Treasury, Division of Property Assessments (published by the Office of Information Resources) publishes a parcel map of 14,722 parcels, rated official here. You can click any parcel on it in Parcel Chart's free map, no sign-in needed.
Has Union County's boundary or name changed?
Union County was created in 1854 from Anderson County, Campbell County, Claiborne County, Grainger County and Knox County. Since then the Atlas of Historical County Boundaries records 43 later changes, most of them small boundary adjustments, chiefly involving Claiborne County, Knox County and Grainger County.
Is my lot in a flood zone?
We do not have flood maps for Union County yet. Look up the address on FEMA's Flood Map Service Center, which shows the effective flood map for any lot.

Nearby

Counties next door