Substantial Changes to Counties
and County Equivalent Entities: 1970-Present

Note:
The Census Bureau does not have maps illustrating the boundary changes listed on this Web page. Contact the state or county governments affected for more specific information about these changes.

This Web page contains substantial county changes only. This includes all county boundary changes affecting at least an estimated population of 200 plus with additional changes of at least one square mile where no estimated population was provided and research indicated that the affected population may have been 200 people or more or "large" annexations of unpopulated territory (10 square miles or more.)

Changes to Counties or County Equivalent Entities: 2000s

New Counties or County Equivalent Entities

• Wrangell City and Borough (02-275):
  Created from part of the former Wrangell-Petersburg Census Area (02-280) and part of Prince of Wales-Outer Ketchikan Census Area (02-201) (Meyers Chuck area) effective June 1, 2008; estimated population: 2,448. The remainder of the former Wrangell-Petersburg Census Area was established as the new Petersburg Census Area (02-195) effective June 1, 2008.
• Petersburg Census Area (02-195):
  Created from the remainder of the former Wrangell-Petersburg Census Area (02-280) when the new Wrangell City and Borough was created effective June 1, 2008; estimated population: 4,260.
• Prince of Wales-Hyder Census Area (02-198):
  Created from the remainder of the former Prince of Wales-Outer Ketchikan Census Area (02-201) after part (Outer Ketchikan area) was annexed by Ketchikan Gateway Borough (02-130) effective May 19, 2008, and part (Meyers Chuck area) included in the new Wrangell City and Borough effective June 1, 2008; estimated population: 6,115.
• Skagway Municipality (02-230):
  Created from part of the former Skagway-Hoonah-Angoon Census Area (02-232) effective June 20, 2007; boundaries are identical to Skagway census subarea; population: 862. The remainder of the former Skagway-Hoonah-Angoon Census Area was established as the new Hoonah-Angoon Census Area (02-105).
• Hoonah-Angoon Census Area (02-105):
  Created from the remainder of the former Skagway-Hoonah-Angoon Census Area (02-232) when the new Skagway Municipality (02-230) was created effective June 20, 2007; population: 2,574.
• Broomfield County, CO (08-014):
  Created from parts of Adams (08-001), Boulder (08-013), Jefferson (08-059), and Weld (08-123) counties effective November 15, 2001. The boundaries of Broomfield County reflect the boundaries of Broomfield city legally in effect on that date; estimated population: 39,177.

• Wrangell-Petersburg Census Area (02-280):
  Split to create part of Wrangell City and Borough (02-275) and all of Petersburg Census Area (02-195), effective June 1, 2008.
• Prince of Wales-Outer Ketchikan Census Area (02-201):
  Part (Outer Ketchikan area) annexed by Ketchikan Gateway Borough (02-130) and part (Meyers Chuck area) included in new Wrangell City and Borough (02-275), remainder renamed Prince of Wales-Hyder Census Area (02-198) effective May 19, 2008.
• Skagway-Hoonah-Angoon Census Area (02-232):
  Split to create Skagway Municipality (02-230) and Hoonah-Angoon Census Area (02-105), effective June 20, 2007.
• Clifton Forge (independent) city, Virginia (51-560):
  Changed to town status and added to Alleghany County (51-005) effective July 1, 2001.

Substantial County or County Equivalent Boundary Changes

• Ketchikan Gateway Borough (02-130):
  Annexed a substantial portion of the former Prince of Wales-Outer Ketchikan Census Area (02-201), including most of the area known as Outer Ketchikan effective May 19, 2008; estimated added population: 7. As a result, the remaining area of the former Prince of Wales-Outer Ketchikan Census Area was renamed Prince of Wales-Hyder Census Area (02-198).
• Adams County, Colorado (08-001):
  Part taken to create new Broomfield County (08-014) effective November 15, 2001; estimated detached population: 15,870.
• Boulder County, Colorado (08-013):
  Part taken to create new Broomfield County (08-014) effective November 15, 2001; estimated detached population: 21,512.
• Jefferson County, Colorado (08-059):
  Part taken to create new Broomfield County (08-014) effective November 15, 2001; estimated detached population: 1,726.
• Weld County, Colorado (08-123):
  Part taken to create new Broomfield County (08-014) effective November 15, 2001; estimated detached population: 69.
• Alleghany County, Virginia (51-005):
  Added the former independent city of Clifton Forge (51-560) effective July 1, 2001; estimated added population: 4,289.
• York County, Virginia (51-199):
  Exchanged territory with Newport News (independent) city (51-700) effective July 1, 2007; estimated net detached population: 293.
• Newport News (independent) city, Virginia (51-700):
  Exchanged territory with York County (51-199) effective July 1, 2007; estimated net added population: 293.

Renamed Counties or County Equivalent Entities

• Doña Ana County, New Mexico (35-013):
  Name corrected from Dona Ana County (added tilde).
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Changes to Counties or County Equivalent Entities: 1990s

New Counties or County Equivalent Entities

• Denali Borough, Alaska (02-068):
  Created from part of the Yukon-Koyukuk Census Area (02-290) and an unpopulated part of the Southeast Fairbanks Census Area (02-240) effective December 7, 1990; 1990 population: 1,682.
• Skagway-Hoonah-Angoon Census Area, Alaska (02-232):
  Created from the remainder of the former Skagway-Yakutat-Angoon Census Area (02-231) when the new Yakutat City and Borough (02-282) was created effective September 22, 1992; 1990 population: 3,679.
• Yakutat City and Borough, Alaska (02-282):
  Created from part of the former Skagway-Yakutat-Angoon Census Area (02-231) effective September 22, 1992. The remainder of the former Skagway-Yakutat-Angoon Census Area was established as the new Skagway-Hoonah-Angoon Census Area (02-232) effective September 22, 1992; 1990 population: 725.

Deleted Counties or County Equivalent Entities

• Skagway-Yakutat-Angoon Census Area, Alaska (02-231):
  Split to create the Skagway-Hoonah-Angoon Census Area (02-232) and Yakutat City and Borough (02-282) effective September 22, 1992.
• Yellowstone National Park (county equivalent), Montana (30-113):
  Annexed to Gallatin (30-031) and Park (30-067) counties effective November 7, 1997.
• South Boston (independent) city, Virginia (51-780):
  Changed to town status and added to Halifax County (51-083) effective June 30, 1995.

Substantial County or County Equivalent Entity Boundary Changes

• Southeast Fairbanks Census Area, Alaska (02-240):
  Unpopulated part taken to create the new Denali Borough (02-068) effective December 7, 1990.
• Yukon-Koyukuk Census Area, Alaska (02-290):
  Part taken to create the new Denali Borough (02-068) effective December 7, 1990; 1990 detached population: 1,682.
• Franklin County, Florida (12-037):
  Boundary correction added unpopulated part of Gulf County (12-045); estimated area added: 10.4 square miles.
• Gulf County Florida (12-045):
  Boundary correction detached unpopulated part to Franklin County (12-037); estimated area detached: 10.4 square miles.
• Montgomery County, Maryland (24-031):
  Added territory (Takoma Park city) from Prince George’s County (24-033) effective July 1, 1997; 1990 added population: 5,156.
• Prince George’s County, Maryland (24-033):
  Lost territory (Takoma Park city) to Montgomery County (24-031) effective July 1, 1997; 1990 detached population: 5,156.
• Gallatin County, Montana (30-031):
  Annexed unpopulated portion of deleted Yellowstone National Park (county equivalent) (30-113) effective November 7, 1997.
• Park County, Montana (30-067):
  Annexed portion of deleted Yellowstone National Park (county equivalent) (30-113) effective November 7, 1997; 1990 added population: 52.
• Carteret County, North Carolina (37-031):
  Boundary correction added from and detached unpopulated parts to Craven County (37-049); estimated area added: five square miles; estimated area detached: 16 square miles.
• Craven County, North Carolina (37-049):
  Boundary correction added from and detached unpopulated parts to Carteret County (37-031); estimated area added: 16 square miles; estimated area detached: five square miles.
• Augusta County, Virginia (51-015):
  Part annexed to Waynesboro (independent) city (51-820) effective July 1, 1994; no estimated population available.
• Bedford County, Virginia (51-019):
  Part annexed to Bedford (independent) city (51-515) effective July 1, 1993; estimated population: 200.
• Fairfax County, Virginia (51-059):
  Parts annexed to Fairfax (independent) city (51-600) effective December 31, 1991 and January 1, 1994; estimated population: 400.
• Halifax County, Virginia (51-083):
  Added the former independent city of South Boston (51-780) effective June 30, 1995.
• Prince William County, Virginia (51-153):
  Part annexed to Manassas Park (independent) city (51-685) effective December 31, 1990; no estimated population available.
• Southampton County, Virginia (51-175):
  Part annexed to Franklin (independent) city (51-620) effective December 31, 1995; estimated population: 400.
• Bedford (independent) city, Virginia (51-515):
  Annexed part of Bedford County (51-019) effective July 1, 1993; estimated population: 200.
• Fairfax (independent) city, Virginia (51-600):
  Annexed parts of Fairfax County (51-059) effective December 31, 1991 and January 1, 1994; estimated population: 400.
• Franklin (independent) city, Virginia (51-620):
  Annexed part of Southampton County (51-175) effective December 31, 1995; estimated population: 400.
• Manassas Park (independent) city, Virginia (51-685):
  Annexed part of Prince William County (51-153) effective December 31, 1990; no estimated population available.
• Waynesboro (independent) city, Virginia (51-820):
  Annexed part of Augusta County (51-015) effective July 1, 1994; no estimated population available.
• Arecibo Municipio, Puerto Rico (72-013):
  Lost territory to Florida Municipio (72-054) effective February 8, 1998; estimated population: 45.
• Barceloneta Municipio, Puerto Rico (72-017):
  Lost territory to Florida Municipio (72-054) effective February 8, 1998; estimated population: 1,860.
• Florida Municipio, Puerto Rico (72-054):
  Gained territory from Arecibo Municipio (72-013), Barceloneta Municipio (72-017), and Manatí Municipio (72-091) effective February 8, 1998; estimated population: 1,905.
• Manatí Municipio, Puerto Rico (72-091):
  Lost territory to Florida Municipio (72-054) effective February 8, 1998; estimated population: 0.
  

Renamed Counties or County Equivalent Entities

• Dade County, Florida (12-025):
  Renamed as Miami-Dade County (12-086) effective July 22, 1997.
• Miami-Dade County, Florida (12-086):
  Renamed from Dade County (12-025) effective July 22, 1997.
• DeKalb County, Indiana (18-033):
  Name corrected from De Kalb County
• LaGrange County, Indiana (18-087):
  Name corrected from Lagrange County.
• LaPorte County, Indiana (18-091):
  Name corrected from La Porte County.
• De Baca County, New Mexico (35-011):
  Name corrected from DeBaca County (erroneously changed in the 1980s).
• McKean County, Pennsylvania (42-083):
  Name corrected from Mc Kean County.
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Changes to Counties or County Equivalent Entities: 1980s

New Counties or County Equivalent Entities

• Aleutians East Borough, Alaska (02-013):
  Created from part of the former Aleutian Islands Census Area (02-010) effective October 23, 1987. The remainder of the former Aleutian Islands Census Area was established as the new Aleutians West Census Area (02-016); 1980 population: 1,643.
• Aleutians West Census Area, Alaska (02-016):
  Created from the remainder of the former Aleutian Islands Census Area (02-010) when the new Aleutians East Borough (02-013) was created effective October 23, 1987; 1980 population: 6,125.
• Lake and Peninsula Borough, Alaska (02-164):
  Created from part of the Dillingham Census Area (02-070) effective April 24, 1989; 1980 population: 1,384.
• Northwest Arctic Borough, Alaska (02-188):
  Created from all of the former Kobuk Census Area (02-140) and an unpopulated part of the North Slope Borough (02-185) effective June 2, 1986; 1980 population: 4,831.
• La Paz County, Arizona (04-012):
  Created from part of Yuma County (04-027) effective January 1, 1983; 1980 population: 12,557.
• Cibola County, New Mexico (35-006):
  Created from part of Valencia County (35-061) effective June 19, 1981; 1980 population: 30,347.

Deleted Counties or County Equivalent Entities

• Aleutian Islands Census Area, Alaska (02-010):
  Split to create the Aleutians East Borough (02-013) and the Aleutians West Census Area (02-016) effective October 23, 1987.
• Kobuk Census Area (02-140):
  All taken plus unpopulated part of the North Slope Borough (02-185) to create the new Northwest Arctic Borough (02-188) effective June 2, 1986.

Substantial County or County Equivalent Entity Boundary Changes

• Dillingham Census Area (02-070):
  Part taken to create the new Lake and Peninsula Borough (02-164) effective April 24, 1989; 1980 detached population: 1,384.
• North Slope Borough (02-185):
  Unpopulated part plus all of the former Kobuk Census Area (02-140) taken to create the new Northwest Arctic Borough (02-188) effective June 2, 1986.
• Yuma County, Arizona (04-027):
  Part taken to create new La Paz County (04-012) effective January 1, 1983; 1980 detached population: 12,557.
• Valencia County, New Mexico (35-061):
  Part taken to create new Cibola County (35-006) effective June 19, 1981; 1980 detached population: 30,347.
• Adams County, Colorado (08-001):
  Annexed part of Denver County (08-031) coextensive with Denver city effective October 18, 1980; estimated population: 2,500. Part annexed to Denver County (08-031) effective May 17, 1988; estimated area 43.31 square miles with no estimated population.
• Arapahoe County, Colorado (08-005):
  Annexed part of Denver County (08-031) coextensive with Denver city effective July 28, 1980; estimated area one square mile with no estimated population.
• Denver County, Colorado (08-001) coextensive with Denver city:
  Part annexed to Adams County (08-001) effective October 18, 1980; estimated population: 2,500. Annexed part of Adams County (08-001) effective May 17, 1988; estimated area 43.31 square miles with no estimated population. Part annexed to Arapahoe County (08-005) effective July 28, 1980; estimated area one square mile with no estimated population.
• Albemarle County, Virginia (51-003):
  Part annexed to Charlottesville (independent) city (51-540) effective February 9, 1988; no estimated population available.
• Augusta County, Virginia (51-015):
  Part annexed to Staunton (independent) city (51-790) effective December 31, 1986; estimated population: 2,300. Part annexed to Waynesboro (independent) city (51-820) effective December 31, 1985; estimated population 3,000.
• Fairfax County, Virginia (51-059):
  Part annexed to Fairfax (independent) city (51-600) effective December 31, 1980; estimated population: 1,100.
• Greensville County, Virginia (51-081):
  Part annexed to Emporia (independent) city (51-595) effective January 1, 1988; estimated population: 400.
• James City County, Virginia (51-095):
  Part annexed to Williamsburg (independent) city (51-830) effective January 1, 1983; estimated population: 400.
• Pittsylvania County, Virginia (51-143):
  Part annexed to Danville (independent) city (51-590) effective December 31, 1987 and December 31, 1988; estimated population: 10,500.
• Prince William County, Virginia (51-153):
  Part annexed to Manassas (independent) city (51-683) effective December 31, 1983; estimated population: 300.
• Rockbridge County, Virginia (51-163):
  Part annexed to Buena Vista (independent) city (51-530) effective December 31, 1983; estimated population: 200.
• Rockingham County, Virginia (51-165):
  Part annexed to Harrisonburg (independent) city (51-660) effective December 31, 1982; estimated population: 5,500.
• Southampton County, Virginia (51-175):
  Part annexed to Franklin (independent) city (51-620) effective December 31, 1985; estimated population: 600.
• Spotsylvania County, Virginia (51-177):
  Part annexed to Fredericksburg (independent) city (51-630) effective December 31, 1983; estimated population: 2,800.
• Buena Vista (independent) city, Virginia (51-530):
  Annexed part of Rockbridge County (51-163) effective December 31, 1983; estimated population: 200.
• Charlottesville (independent) city, Virginia (51-540):
  Annexed part of Albemarle County (51-003) effective February 9, 1988; no estimated population available.
• Danville (independent) city, Virginia (51-590):
  Annexed part of Pittsylvania County (51-143) effective December 31, 1987 and December 31, 1988; estimated population: 10,500.
• Emporia (independent) city, Virginia (51-595):
  Annexed part of Greensville County (51-081) effective January 1, 1988; estimated population: 400.
• Fairfax (independent) city, Virginia (51-600):
  Annexed part of Fairfax County (51-059) effective December 31, 1980; estimated population: 1,100.
• Franklin (independent) city, Virginia (51-620):
  Annexed part of Southampton County (51-175) effective December 31, 1985; estimated population: 600.
• Fredericksburg (independent) city, Virginia (51-630):
  Annexed part of Spotsylvania County (51-177) effective December 31, 1983; estimated population: 2,800.
• Harrisonburg (independent) city, Virginia (51-660):
  Annexed part of Rockingham County (51-165) effective December 31, 1982; estimated population: 5,500.
• Manassas (independent) city, Virginia (51-683):
  Annexed part of Prince William County (51-153) effective December 31, 1983; estimated population: 300.
• Staunton (independent) city, Virginia (51-790):
  Annexed part of Augusta County (51-015) effective December 31, 1986; estimated population: 2,300.
• Waynesboro (independent) city, Virginia (51-820):
  Annexed part of Augusta County (51-015) effective December 31, 1985; estimated population: 3,000.
• Williamsburg (independent) city, Virginia (51-830):
  Annexed part of James City County (51-095) effective December 31, 1983; estimated population: 400.

Renamed Counties or County Equivalent Entities

• DeKalb County, Alabama (01-049):
  Name corrected from De Kalb County.
• DeSoto County, Florida (12-027):
  Name corrected from De Soto County.
• DeKalb County, Georgia (13-089):
  Name corrected from De Kalb County.
• DeKalb County, Illinois (17-037):
  Name corrected from De Kalb County.
• DuPage County, Illinois (17-043):
  Name corrected from Du Page County.
• DeSoto County, Mississippi (28-033):
  Name corrected from De Soto County.
• DeKalb County, Missouri (29-063):
  Name corrected from De Kalb County.
• LaMoure County, North Dakota (38-045):
  Name corrected from La Moure County.
• DeKalb County, Tennessee (47-041):
  Name corrected from De Kalb County.
• DeWitt County, Texas (48-123):
  Name corrected from De Witt County.
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Changes to Counties or County Equivalent Entities: 1970s

Changes to County Equivalent Entities in Alaska

• The county equivalent entities in Alaska changed from Census Divisions in 1970 to Boroughs and Census Areas in 1980. The inventory and boundaries of the Alaska county-level entities changed substantially during the decade.
• New entities created in Alaska are: Dillingham Census Area (02-070), North Slope Borough (02-185), and Valdez-Cordova Census Area (02-261).

Deleted county equivalent entities in Alaska

• Angoon Division (02-030)
• Barrow Division (02-040)
• Cordova-McCarthy Division (02-065)
• Kenai-Cook Inlet Division (02-120)
• Kuskokwim Division (02-160)
• Outer Ketchikan Division (02-190)
• Prince of Wales Division (02-200)
• Skagway-Yakutat Division (02-230)
• Upper Yukon Division (02-250)
• Valdez-Chitina-Whittier Division (02-260)

New Counties or County Equivalent Entities

• Manassas (independent) city, Virginia (51-683):
  Changed from a town to a city and became independent of Prince William County (51-153) effective June 1, 1975; 1970 population: 9,164.
• Manassas Park (independent) city, Virginia (51-685):
  Changed from a town to a city and became independent of Prince William County (51-153) effective May 1, 1975; 1970 population: 6,844.
• Poquoson (independent) city, Virginia (51-735):
  Changed from a town to a city and became independent of York County (51-199) effective June 1, 1975; 1970 population: 5,441.

Deleted Counties or County Equivalent Entities

• Washabaugh County, South Dakota (46-131):
  Combined into Jackson County (46-071) effective January 1, 1979.
• Nansemond County, Virginia (51-123):
  Combined into Suffolk (independent) city (51-800) effective July 1, 1972.

Substantial County or County Equivalent Entity Boundary Changes

• Jackson County, South Dakota (46-071):
  Added all of the former Washabaugh County (46-131), effective January 1, 1979.
• Bedford County, Virginia (51-019):
  Part annexed to Lynchburg (independent) city (51-520), effective December 31, 1975; estimated population: 1,500.
• Campbell County, Virginia (51-031):
  Part annexed to Lynchburg (independent) city (51-520) effective December 31, 1975; estimated population: 9,000.
• Dinwiddie County, Virginia (51-053):
  Part annexed to Petersburg (independent) city (51-730) effective December 31, 1971; estimated population: 3,400.
• Frederick County, Virginia (51-069):
  Part annexed to Winchester (independent) city (51-840) effective December 31, 1970; estimated population: 4,800.
• Montgomery County, Virginia (51-121):
  Part annexed to Radford (independent) city (51-750) effective December 31, 1976; estimated population: 400.
• Prince George County, Virginia (51-149):
  Part annexed to Petersburg (independent) city (51-730) effective December 31, 1975; estimated population: 4,700.
• Prince William County, Virginia (51-153):
  Part taken when Manassas (51-683) and Manassas Park (51-685) became cities and separated from the county effective June 1, 1975, and May 1, 1975, respectively; 1970 population detached: 16,008.
• Roanoke County, Virginia (51-161):
  Part annexed to Roanoke (independent) city (51-770) effective December 31, 1975; estimated population: 13,500.
• Washington County, Virginia (51-191):
  Part annexed to Bristol (independent) city (51-520); estimated population: 4,800.
• York County, Virginia (51-199):
  Part taken when Poquoson (51-735) became a city and separated from the county effective June 1, 1975; 1970 population detached: 5,441.
• Bristol (independent) city, Virginia (51-520):
  Annexed part of Washington County (51-191); estimated population: 4,800.
• Lynchburg (independent) city, Virginia (51-680):
  Annexed part of Bedford County (51-019) effective December 31, 1975; estimated population: 1,500. Annexed part of Campbell County (51-031) effective December 31, 1975; estimated population: 9,000.
  
• Petersburg (independent) city, Virginia (51-730):
  Annexed part of Dinwiddie County (51-053) effective December 31, 1971; estimated population: 3,400. Annexed part of Prince George County (51-149) effective December 31, 1971; estimated population: 4,700.
  
• Radford (independent) city, Virginia (51-750):
  Annexed part of Montgomery County (51-121) effective December 31, 1976; estimated population: 400.
• Roanoke (independent) city, Virginia (51-770):
  Annexed part of Roanoke County (51-161) effective December 31, 1975; estimated population: 13,500.
• Suffolk (independent) city, Virginia (51-800):
  Added all of former Nansemond County (51-123) effective July 1, 1972.
• Winchester (independent) city, Virginia (51-840):
  Annexed part of Frederick County (51-069) effective December 31, 1970; estimated population: 4,800.
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Note: The Census Bureau does not have maps illustrating the boundary changes listed on this Web page. Contact the state or county governments affected for more specific information about these changes.

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Page Last Modified: May 27, 2009