County Composition of Metropolitan Areas, 1930 - 2006

(Go Back to County Composition of Nineteenth-Century Metropolitan Areas Index)

The lowest level of geography in the 2005 and 2006 ACS was the PUMA, which had the exact same boundaries as the 2000 PUMA Census data. The Census Bureau has not released information associating these PUMA boundaries with 2005 and 2006 metropolitan area definitions. For this reason, the 2005 and 2006 ACS versions of METAREA present classifications based on metropolitan boundaries from 2000. The 2005 and 2006 METAREA variable is thus consistent with 2000 metropolitan area definitions. Because of this, the Composition of Metropolitan areas for the 2005 and 2006 ACS correspond to the 2000 composition.

Code City/State 1930 1940-1950 1970 1980 1990 2000; 2005; 2006
160 Albany-Schenectady-Troy, NY Albany Albany Albany Albany Albany Albany
Rensselaer Rensselaer Rensselaer Montgomery Greene Montgomery
Schenectady Schenectady Saratoga Rensselaer Montgomery Rensselaer
Schenectady Saratoga Rensselaer Saratoga
Schenectady Saratoga Schenectady
Schenectady Schoharie 
520 Atlanta, GA DeKalb Cobb** Clayton Butts Barrow Barrow 
Fulton De Kalb Cobb Cherokee Butts Bartow 
Fulton De Kalb Clayton Cherokee Carroll 
Fulton Cobb Clayton Cherokee 
Gwinnett De Kalb Cobb Clayton 
Douglas Coweta Cobb 
Fayette De Kalb Coweta 
Forsyth Douglas DeKalb 
Fulton Fayette Douglas 
Gwinnet Forsyth Fayette 
Henry Fulton Forsyth 
Newton Gwinnet Fulton 
Paulding Henry Gwinnett 
Rockdale Newton Henry 
Walton Paulding Newton 
Rockdale Paulding 
Spaulding Pickens 
Walton Rockdale 
Spalding 
Walton 
Code City/State 1930 1940-1950 1970 1980 1990 2000; 2005; 2006
720 Baltimore, MD # Baltimore Anne Arundel Anne Arundel Anne Arundel Anne Arundel Anne Arundel
Baltimore City *** Baltimore Baltimore Baltimore Baltimore Baltimore
Baltimore City *** Baltimore City *** Baltimore City *** Baltimore City *** Baltimore City *
Carroll Carroll Caroll Carroll
Harford Harford Harford Harford
Howard Howard Howard Howard
Queen Anne's Queen Anne's
1120 Boston, MA # Essex Essex Essex (p) Essex (p) Bristol Bristol (p)
Middlesex Middlesex Middlesex (p) Middlesex (p) Essex (p) Essex (p)
Norfolk Norfolk Norfolk (p) Norfolk (p) Middlesex (p) Middlesex (p)
Suffolk Suffolk Plymouth (p) Plymouth (p) Norfolk (p) Norfolk (p)
Suffolk Suffolk Plymouth (p) Plymouth (p)
Suffolk Suffolk
Worcester (p) Worcester (p)
Rockingham , NH (p)
1160 Bridgeport, CT Fairfield Fairfield Fairfield (p) Fairfield (p) Fairfield (p) Fairfield (p)
New Haven (p) New Haven (p) New Haven (p) New Haven (p)
1280 Buffalo, NY # Erie Erie Erie Erie Erie Erie 
Niagara Niagara Niagara Niagara Niagara 
1281 Niagara Falls, NY
1440 Charleston, SC Charleston Charleston Berkeley Berkeley Berkeley Berkeley
Charleston Charleston Charleston Charleston
Dorchester Dorchester Dorchester
Code City/State 1930 1940-1950 1970 1980 1990 2000; 2005; 2006
1600 Chicago, IL # Cook Cook Cook Cook Cook Cook
Dupage Dupage Dupage Dupage Dupage DeKalb 
Lake, IL Kane** Kane Kane McHenry DuPage
Lake, IN Lake, IL Lake, IL Lake, IL Grundy 
McHenry** McHenry McHenry Kane 
Will Will Will Kendall 
Lake, IN Lake 
McHenry 
Will 
1601 Aurora-Elgin, IL Kane
Kendell
1602 Gary-Hammond,IN # Lake, IN Lake, IN Lake, IN Lake, IN
Porter Porter Porter Porter
1603 Joliet, IL Grundy
Will
1604 Lake, IL Lake, IL
1640 Cincinatti-Hamilton, OH-KY-IN Hamilton Hamilton Clermont Clermont Clermont Dearborn , IN
Campbell, KY Campbell, KY Hamilton Hamilton Hamilton Ohio , IN
Kenton, KY Kenton, KY Warren Warren Warren Boone , KY
Boone, KY Boone, KY Boone, KY Campbell , KY
Campbell, KY Campbell, KY Campbell, KY Gallatin , KY
Kenton, KY Kenton, KY Kenton, KY Grant , KY
Dearborn, IN Dearborn, IN Dearborn, IN Kenton , KY
Pendleton , KY
Brown , OH
Clermont , OH
Hamilton , OH
Warren , OH
1680 Cleveland, OH Cuyahoga Cuyahoga Cuyahoga Cuyahoga Cuyahoga Ashtabula 
Lake Lake Geauga Geauga Geauga Cuyahoga
Lake Lake Lake Geauga
Medina Medina Medina Lake
Lorain 
Medina
Code City/State 1930 1940-1950 1970 1980 1990 2000; 2005; 2006
1840 Columbus, OH Franklin Franklin Delaware Delaware Delaware Delaware
Franklin Fairfield Fairfield Fairfield
Pickaway Franklin Franklin Franklin
Madison Licking Licking
Pickaway Madison Madison
Pickaway Pickaway
Union
2000 Dayton-Springfield, OH-KY-IN Greene** Greene Greene Clark Clark
Montgomery** Miami Miami Greene Greene
Montgomery Montgomery Miami Miami
Preble Preble Montgomery Montgomery
2001 Springfield, OH # Clark Clark Clark Champaign
Clark
2080 Denver, CO # Arapahoe Adams** Adams Adams Adams Adams
Denver Arapahoe Arapahoe Arapahoe Arapahoe Arapahoe
Jefferson Denver Boulder Boulder Denver Denver
Jefferson Denver Denver Douglas Douglas
Jefferson Douglas Jefferson Jefferson
Gilpin
Jefferson
2081 Boulder-Longmont,CO # Boulder
Code City/State 1930 1940-1950 1970 1980 1990 2000; 2005; 2006
2120 Des Moines, IA Polk Polk Polk Polk Dallas Dallas
Warren Polk Polk
Warren Warren
2160 Detroit, MI Macomb Macomb Macomb Lapeer Lapeer Lapeer 
Oakland Oakland Oakland Livingston Livingston Macomb 
Wayne Wayne Wayne Macomb Macomb Monroe 
Oakland Monroe Oakland 
St. Clair Oakland St. Clair 
Wayne St. Clair Wayne 
Wayne
2240 Duluth-Superior, MN-WI St. Louis St. Louis St. Louis St. Louis St. Louis St. Louis
Douglas, WI Douglas, WI Douglas, WI Douglas, WI Douglas, WI Douglas, WI
2360 Erie, PA Erie Erie Erie Erie Erie Erie
2440 Evansville, IN-KY Vanderburg Vanderburg Vanderburg Gibson Posey Posey
Warrick Posey Vanderburg Vanderburgh
Henderson, KY Vanderburg Warrick Warrick
Warrick Henderson, KY Henderson, KY
Henderson, KY
3000 Grand Rapids, MI Kent Kent Kent Kent Kent Allegan 
Ottawa Ottawa Ottawa Kent 
Muskegon 
Ottawa 
3240 Harrisburg-Leban- Carlisle,PA Cumberland Cumberland Cumberland Cumberland Cumberland Cumberland
Dauphin Dauphin Dauphin Dauphin Dauphin Dauphin
Perry Perry Lebanon Lebanon
Perry Perry
Code City/State 1930 1940-1950 1970 1980 1990 2000; 2005; 2006
3280 Hartford, CT Hartford Hartford Hartford (p) Hartford (p) Hartford (p) Hartford (p)
Middlesex Litchfield (p) Litchfield (p) Litchfield (p)
Tolland Middlesex (p) Middlesex (p) Middlesex (p)
New London (p) New London (p) New London (p)
Tolland (p) Tolland (p) Tolland (p)
Windham  (p)
3281 Bristol, CT Hartford (p) Hartford (p) Hartford (p)
Litchfield (p) Litchfield (p) Litchfield (p)
3282 Middletown, CT Middlesex (p)
3283 New Britian, CT Hartford (p) Hartford (p) Hartford (p)
3480 Indianapolis, IN Marion Marion Boone Boone Boone Boone 
Hamilton Hamilton Hamilton Hamilton 
Hancock Hancock Hancock Hancock 
Hendricks Hendricks Hendricks Hendricks 
Johnson Johnson Johnson Johnson 
Marion Marion Marion Madison 
Morgan Morgan Morgan Marion 
Shelby Shelby Shelby Morgan 
3760 Kansas City, MO-KS Jackson Cass** Cass Cass Cass Johnson , KS
Wyandotte, KS Clay** Clay Clay Clay Leavenworth , KS
Jackson Jackson Jackson Jackson Miami , KS
Johnson, KS Platte Platte Lafayette Wyandotte , KS
Wyandotte, KS Johnson, KS Ray Platte Cass 
Wyandotte, KS Johnson, KS Ray Clay 
Wyandotte, KS Johnson, KS Clinton 
Leavenworth, KS Jackson 
Miami, KS Lafayette 
Wyandotte, KS Platte 
Ray 
4360 Lincoln, NE Lancaster Lancaster Lancaster Lancaster Lancaster Lancaster
Code City/State 1930 1940-1950 1970 1980 1990 2000; 2005; 2006
4480 Los Angeles-Long Beach,CA # Los Angeles Los Angeles Los Angeles Los Angeles Los Angeles Los Angeles
Orange Orange
San Bernardino
4481 Anaheim-Santa Ana, CA Orange Orange Orange
4520 Louisville, KY-IN Jefferson Jefferson Jefferson Bullitt Bullitt Bullitt 
Clark, IN Clark, IN Clark, IN Jefferson Jefferson Jefferson 
Floyd, IN Floyd, IN Floyd, IN Oldham Oldham Oldham 
Clark, IN Shelby Scott , IN
Floyd, IN Clark, IN Clark , IN
Floyd, IN Floyd , IN
Harrison, IN Harrison , IN
4760 Manchester, NH Hillsborough Hillsborough Hillsborough (p) Hillsborough (p) Hillsborough (p) Hillsborough (p)
Merrimack (p) Merrimack (p) Merrimack (p) Merrimack (p)
Rockingham (p) Rockingham (p) Rockingham (p)
4920 Memphis, TN-AR-MS Shelby Shelby Shelby Shelby Shelby Shelby
Crittenden, AR Tipton Tipton Tipton
Crittendon, AR Crittendon, AR Crittendon, AR
De Soto, MS De Soto, MS De Soto, MS
5080 Milwaukee-Waukesha, WI Milwaukee Milwaukee Milwaukee Milwaukee Milwaukee Milwaukee
Waukesha Waukesha Ozaukee Ozaukee Ozaukee Ozaukee
Washington Washington Washington Washington
Waukesha Waukesha Waukesha Waukesha
Code City/State 1930 1940-1950 1970 1980 1990 2000; 2005; 2006
5120 Minneapolis-St. Paul, MN Hennepin Anoka** Anoka Anoka Anoka Anoka
Ramsey Dakota** Dakota Carver Carver Carver
Hennepin Hennepin Chisago Chisago Chisago
Ramsey Ramsey Dakota Dakota Dakota
Washington Hennepin Hennepin Hennepin
Ramsey Isanti Isanti
Scott Ramsey Ramsey
Washington Scott Scott
Wright Sherburne Sherburne
St. Croix, Wi Washington Washington
Wright Wright
St. Croix, Wi St. Croix, WI
Pierce , WI
5360 Nashville, TN Davidson Davidson Davidson Cheathem Cheathem Cheathem
Sumner Davidson Davidson Davidson
Williamson Dickson Dickson Dickson
Robertson Robertson Robertson
Rutherford Rutherford Rutherford
Sumner Sumner Sumner
Williamson Williamson Williamson
Wilson Wilson Wilson
Code City/State 1930 1940-1950 1970 1980 1990 2000; 2005; 2006
5480 New Haven-Meriden, CT New Haven New Haven New Haven (p) Middlesex (p) Middlesex (p) Middlesex, (p)
Litchfield New Haven (p) New Haven (p) New Haven (p)
5560 New Orleans, LA Jefferson Jefferson Jefferson Jefferson Jefferson Jefferson
Orleans Orleans Orleans Orleans Orleans Orleans
St. Bernard** St. Bernard St. Bernard St. Bernard St. Bernard
St. Tammany St. Tammany St. Charles St. Charles
St. John The Baptist St. John the Baptist
St. Tammany St. Tammany
Plaquemines 
St. James 
5600 New York, NY # Bronx Bronx Bronx Bronx Bronx Bronx
Kings Kings Kings Kings Kings Kings
Nassau Nassau New York New York New York New York
New York New York Queens Putnam Putnam Putnam
Queens Queens Richmond Queens Queens Queens
Richmond Richmond Nassau Richmond Richmond Richmond
Rockland Rockland Rockland Rockland Rockland Rockland
Suffolk Westchester Suffolk Westchester Westchester Westchester
Westchester Bergen, NJ Westchester Bergen, NJ
Bergen, NJ Essex, NJ
Essex, NJ Hudson, NJ
Hudson, NJ Middlesex, NJ
Middlesex, NJ Morris, NJ
Morris, NJ Passaic, NJ
Passaic, NJ Somerset, NJ
Somerset, NJ Suffolk, NJ
Union, NJ Union, NJ
Code City/State 1930 1940-1950 1970 1980 1990 2000; 2005; 2006
5601 Nassau-Suffolk, NY Nassau Nassau
Suffolk Suffolk
5602 Bergen-Passaic #/ Patterson-Clifton, NJ # Bergen Passaic Bergen
Passaic Passaic
5603 Jersey City, NJ Hudson Hudson Hudson
5604 Middlesex-Somerset- Hunt, NJ Hunterdon
Middlesex
Somerset
5605 Newark, NJ Essex Essex Essex Essex
Morris Morris Morris Morris
Union Somerset Sussex Sussex
Union Union Union
Warren 
5920 Omaha, NE-IA Douglas Douglas Douglas Douglas Douglas Douglas
Pottawattamie, IA Sarpy Sarpy Sarpy Sarpy Sarpy
Pottawamie, IA Pottawamie, IA Pottawamie, IA Washington Washington
Pottawamie, IA Pottawattamie, IA
Cass , NE
6120 Peoria, IL Peoria Peoria Peoria Peoria Peoria Peoria
Tazewell Tazewell Tazewell Tazewell Tazewell Tazewell
Woodford Woodford Woodford Woodford
Code City/State 1930 1940-1950 1970 1980 1990 2000; 2005; 2006
6160 Philadelphia, PA-NJ Bucks Bucks Bucks Bucks Bucks Bucks, PA
Delaware Chester** Chester Chester Chester Chester, PA
Montgomery Delaware Delaware Delaware Delaware Delaware, PA
Philadelphia Montgomery Montgomery Montgomery Montgomery Montgomery, PA
Burlington, NJ Philadelphiaia Philadelphiaia Philadelphiaia Philadelphiaia Philadelphia, PA
Camden, NJ Burlington, NJ Burlington, NJ Burlington, NJ Burlington, NJ Burlington, NJ
Gloucester, NJ Camden, NJ Camden, NJ Camden, NJ Camden, NJ Camden, NJ
Gloucester, NJ Gloucester, NJ Gloucester, NJ Gloucester, NJ Gloucester, NJ
Salem , NJ
6280 Pittsburgh, PA Allegheny Allegheny Allegheny Allegheny Allegheny Allegheny
Beaver Beaver Beaver Beaver Fayette Fayette
Westmoreland Washington** Washington Washington Washington Washington
Westmoreland Westmoreland Westmoreland Westmoreland Westmoreland
Beaver Beaver 
Butler 
6400 Portland, ME Cumberland Cumberland (p) Cumberland (p) Cumberland (p) Cumberland (p) Cumberland (p)
York (p) York (p) York (p)
6440 Portland-Vancouver, OR-WA Clackamas Clackamas Clackamas Clackamas Clackamas Clackamas
Multnomah Multnomah Multnomah Multnomah Multnomah Multnomah
Washington** Washington Washington Washington Washington
Clark, WA Clark, WA Clark, WA Yamhill Yamhill
6441 Vancouver, WA Clark, WA Columbia
Clark, WA
Code City/State 1930 1940-1950 1970 1980 1990 2000; 2005; 2006
6480 Providence, RI Bristol Bristol Bristol Bristol Bristol Bristol
Kent Kent Kent Kent Kent Kent (p)
Providence Providence Newport (p) Newport (p) Newport (p) Newport (p)
Providence (p) Providence (p) Providence (p) Providence (p)
Washington (p) Washington (p) Washington (p) Washington (p)
Bristol, MA (p) Bristol, MA (p) Bristol, MA (p)
Norfolk, MA (p) Norfolk, MA (p)
Worcester, MA (p) Worcester, MA (p)
6481 Fall River, MA-RI Bristol Bristol Bristol (p) Bristol (p) Bristol (p)
Newport, RI (p) Newport, RI (p) Newport, RI (p)
6482 Pawtuckett,RI-MA Providence (p)
Bristol, MA (p)
Norfolk, MA (p)
Worcester, MA (p)
6680 Reading, PA Berks Berks Berks Berks Berks Berks
6760 Richmond-Petersburg, VA # Chesterfield Chesterfield Chesterfield Charles City Charles City Charles City
Henrico Henrico Hanover Chesterfield Chesterfield Chesterfield
Richmond City *** Richmond City *** Henrico Goochland Dinwiddie Dinwiddie
Richmond City *** Hanover Goochland Goochland
Henrico Hanover Hanover
New Kent Henrico Henrico
Powhatan New Kent New Kent
Richmond City *** Powhatan Powhatan
Prince George Prince George
Richmond City *** Richmond City *
Colonial Heights city *
Hopewell city *
Petersburg city *
Code City/State 1930 1940-1950 1970 1980 1990 2000; 2005; 2006
6761 Petersburg-Col. Heights- Hopewell, VA Prince George Prince George
Dinwiddie Dinwiddie
6840 Rochester, NY Monroe Monroe Livingston Livingston Livingston Livingston
Monroe Monroe Monroe Monroe
Orleans Ontario Ontario Ontario
Wayne Orleans Orleans Orleans
Wayne Wayne Wayne
Genesee 
7000 St. Joseph, MO Buchanan Buchanan Buchanan Andrew Buchanan Andrew 
Buchanan Buchanan
7040 St. Louis, MO-IL # St. Louis St. Charles Franklin Franklin Franklin Franklin
St. Louis City *** St. Louis Jefferson Jefferson Jefferson Jefferson
Madison, IL St. Louis City *** St. Charles St. Charles St. Charles St. Charles
St. Clair, IL Madison, IL St. Louis St. Louis St. Louis St. Louis
St. Clair, IL St. Louis City *** St. Louis City *** St. Louis City *** St. Louis City *
Madison, IL Clinton, IL Clinton, IL Clinton, IL
St. Clair, IL Madison, IL Jersey, IL Jersey, IL
Monroe, IL Madison, IL Madison, IL
St. Clair, IL Monroe, IL Monroe, IL
St. Clair, IL St. Clair, IL
Crawford (p)
Lincoln
Warren
Code City/State 1930 1940-1950 1970 1980 1990 2000; 2005; 2006
7160 Salt Lake City-Ogden, UT # Salt Lake Salt Lake Davis Davis Davis Davis
Salt Lake Salt Lake Salt Lake Salt Lake
Tooele Weber Weber
Weber
7161 Ogden, UT Weber** Weber
7240 San Antonio, TX Bexar Bexar Bexar Bexar Bexar Bexar
Guadalupe Comal Comal Comal
Guadalupe Guadalupe Guadalupe
Wilson 
7360 San Francisco-Oakland, Alameda Alameda Alameda Alameda Marin Marin
CA # San Francisco
Contra Costa Contra Costa Contra Costa Contra Costa San Francisco San Mateo
Marin Marin Marin Marin San Mateo
San Francisco San Francisco San Francisco San Francisco
San Mateo San Mateo San Mateo San Mateo
Santa Clara Solano
7361 Oakland, CA Alameda
Contra Costa
7362 Vallejo-Fairfield-Napa, CA Napa Napa Napa
Solano Solano Solano
7520 Savannah, GA Chatham Chatham Chatham Bryan Chatham Chatham
Chatham Effingham Effingham
Effingham Bryan 
Code City/State 1930 1940-1950 1970 1980 1990 2000; 2005; 2006
7560 Scranton-Wilkes-Barre, Hazleton, PA Lackawanna Lackawanna Lackawanna Lackawanna Columbia Columbia
Luzerne Lackawanna Lackawanna
Monroe Luzerne Luzerne
Monroe Wyoming
Wyoming
7561 Wilkes-Barre- Luzerne Luzerne Luzerne
Hazleton, PA
7600 Seattle-Everett, WA King King King King King King
Snohomish Snohomish Snohomish Snohomish Snohomish Snohomish
Island 
8000 Springfield-Holyhoke, MA Hampden Hampden Hampden Hampden Hampden Hamden (p)
Hampshire Hampshire Hampshire Hampshire Hampshire Hampshire (p)
Worcester (p) Worcester (p) Franklin (p)
Tolland, CT (p) Tolland, CT (p)
8160 Syracuse, NY Onondaga Onondaga Madison Madison Madison Madison
Onondaga Onondaga Onondaga Onondaga
Oswego Oswego Oswego Oswego
Cayuga 
8400 Toledo, OH-MI Lucas Lucas Lucas Fulton Fulton Fulton
Wood Wood Lucas Lucas Lucas
Monroe, MI Ottawa Wood Wood
Wood
Monroe, MI
8480 Trenton, NJ Mercer Mercer Mercer Mercer Mercer Mercer
8680 Utica-Rome, NY Herkimer Herkimer Herkimer Herkimer Herkimer Herkimer
Oneida Oneida Oneida Oneida Oneida Oneida
Code City/State 1930 1940-1950 1970 1980 1990 2000; 2005; 2006
8840 Washington DC- MD-VA-WV # Washington District of Columbia District of Columbia District of Columbia District of Columbia District of Columbia
Montgomery, MD Montgomery, MD Montgomery, MD Charles, MD Calvert, MD Calvert , MD
Prince George's, MD Prince George's, MD Prince George's, MD Montgomery, MD Charles, MD Charles , MD
Alexandria City *** Alexandria City *** Alexandria City *** Prince George's, MD Frederick, MD Frederick , MD
Arlington, VA Arlington, VA Arlington, VA Alexandria City *** Montgomery, MD Montgomery , MD
Fairfax, VA Fairfax, VA Arlington, VA Prince George's, MD Prince George's , MD
Falls Church City, VA Loudoun, VA Fairfax, VA Alexandria City *** Arlington , VA
Prince William, VA Loudoun, VA Arlington, VA Clarke , VA
Fairfax City, VA Prince William, VA Fairfax, VA Culpeper , VA
Loudoun, VA Fairfax , VA
Prince William, VA Fauquier , VA
Stafford, VA King George , VA
Loudoun , VA
Prince William , VA
Spotsylvania , VA
Stafford , VA
Warren , VA
Alexandria city, VA
Fairfax city, VA
Falls Church city, VA
Fredericksburg city, VA
Manassas city, VA
Manassas Park city, VA
Berkeley , WV
Jefferson , WV
9160 Wilmington, DE-NJ-MD New Castle New Castle New Castle New Castle New Castle New Castle
Salem, NJ Salem, NJ Salem, NJ Salem, NJ Salem, NJ Cecil, MD
Cecil, MD Cecil, MD Cecil, MD
9240 Worcester, MA Worcester Worcester Worcester (p) Worcester (p) Worcester (p) Worcester (p)
Windham , CT (p)
Hampden , MA (p)

Table Notes

** County became part of metropolitan area in 1950.
*** Independent City, not politically incorporated within a county.
(p) Part of county.

# City-Specific Notes

Baltimore, MD Baltimore became an independent city in the 1850s.

Bergen/Passaic, NJ In 1970, Bergen and Passiac counties were included in the Patterson/Clifton, NJ metro area. Passaic County remained in the Patterson/Clifton metro in 1980 but Bergen County was defined as part of the New York metro area. In 1990, the two counties were defined as their own metro area.

Boston, MA The 1940 and 1950 PUMS use New England County Metropolitan Areas. All other samples use towns and cities rather than counties.

Boulder, CO Boulder was included in the Denver metro area in 1970 and 1980 but was made a separate Primary Metro in 1990.

Buffalo, NY The Census Bureau identified Niagara Falls as a Primary Metro in 1990. From 1920 to 1980 Niagara Falls is separate metropolitan area.

Chicago, IL Gary-Hammond, IN is designated as a separate metropolitan area beginning in 1970.

Denver, CO Between 1900 and 1910, Denver became an independent city. In 1900 Denver was a part of Arapahoe County but annexed territory from that county and became independent by 1910. The only area meeting the criteria for metropolitan status in 1910 and 1920 was the city of Denver. Boulder was included in the Denver metropolitan area in 1970 and 1980 but was made a separate Primary Metro in 1990.

Gary-Hammond, IN Gary-Hammond, IN is designated as a separate metropolitan area beginning in 1970.

Los Angeles, CA San Bernardino was included in Los Angeles in 1930 but became an independent metropolitan are from 1930 through 1990.

New York, NY The New York metropolitan area has substantial rearrangement of counties due to the splitting of the area into smaller Primary Metros. This causes some counties, such as Bergen, to move among multiple metro areas over the last forty years. (See Bergen/Passaic, above, and Patterson/Clifton, below).

Patterson/Clifton, NJ In 1970, Bergen and Passiac counties were included in the Patterson/Clifton, NJ metro area. Passaic County remained in the Patterson/Clifton metro in 1980 but Bergen County was defined as part of the New York metro area. In 1990, the two counties were defined as their own metro area.

Richmond, VA The independent city of Manchester is included in the Richmond metropolitan area in 1900 and 1910. Richmond annexed Manchester between 1900 and 1910. Since Richmond also annexed part of Henricko County, the unannexed remainder of Henrico County failed to meet the criteria for inclusion in the metro area in 1920.

Riverside-San Bernaradino, CA See Los Angeles, above.

St. Louis, MO The city of St. Louis was an independent city by 1880.

Salt Lake City, UT Ogden, UT, was a separate metropolitan area in 1940 and 1950 but was combined with Salt Lake City in 1980.

San Francisco, CA Alameda and Contra Costa counties were split from the San Francisco metropolitan area in 1990 and became the Oakland metropolitan area. Solano County was part of the San Francisco metro area in 1940 and 1950, failed to meet metro criteria in 1960 but emerged as the separate metro area of Vallejo from 1970 to 1990.

Springfield, OH Springfield was a separate metropolitan area from 1920 to 1980 but was included in the Dayton metropolitan area in 1990.

Vallejo, CA See San Francisco, above.

Washington, DC Alexandria was an independent city by 1900. Arlington County changed its name from Alexandria County between 1910 and 1920.

(Go Back to County Composition of Nineteenth-Century Metropolitan Areas Index)