# Geography

## Centers of Population

The concept of the center of population as used by the U.S. Census Bureau is that of a balance point. The center of population is the point at which an imaginary, weightless, rigid, and flat (no elevation effects) surface representation of the 50 states (or 48 conterminous states for calculations made prior to 1960) and the District of Columbia would balance if weights of identical size were placed on it so that each weight represented the location of one person.

### Related Documentation

• Centers of Population Computation Documentation [PDF]
Methodology used by the U.S. Census Bureau for the computation of the centers of population from 1950 to 2010.
• Facts for Features
A special edition about the 2010 Centers of Population.
• Mean Center of Population Relative Shift by Decade:  1790 to 2010  [PPT]   [PDF]
This series of plots provides a way to view the variations in movement and distance from one mean center of population to another.  In these slides, the compass on the right marks the starting decade for each pair of centers.  The second decade's center is plotted in relation to the compass point, with the length and angle of the line indicating the relative distance and directionality of movement.  The final slide highlights the decade with the greatest distance of movement (1860), shortest distance (1920), most northerly direction (1870), and most southerly (2010).

### Data Files

#### Mean Center of Population for the United States:  2010

Text file containing population and latitude and longitude coordinates for the mean center of population for the United States for the 2010 Census.

#### Median Center of Population for the United States:  2010

Text file containing population and latitude and longitude coordinates for the median center of population for the United States for the 2010 Census.

#### Centers of Population by State:  2010

Text file containing population and mean centers of population by state/state equivalent entity for the 2010 Census. The record layout is:

• STATEFP:  2-character state FIPS code
• STNAME:  state name
• POPULATION:  2010 Census population tabulated for the state
• LATITUDE:  latitude coordinate for the center of population for the state
• LONGITUDE:  longitude coordinate for the center of population for the state

#### Centers of Population by County:  2010

State/state equivalent entity-based text files containing the mean centers of population for each county/county equivalent entity within a state/state equivalent entity for the 2010 Census. The record layout is:

• STATEFP:  2-character state FIPS code
• COUNTYFP:  3-character county FIPS code
• COUNAME:  county name
• STNAME:  state name
• POPULATION:  2010 Census population tabulated for the county
• LATITUDE:  latitude coordinate for the center of population for the county
• LONGITUDE:  longitude coordinate for the center of population for the county

#### Centers of Population by Census Tract:  2010

State/state equivalent entity-based text files containing the mean centers of population for each census tract within a state/state equivalent entity for the 2010 Census. The record layout is:

• STATEFP:  2-character state FIPS code
• COUNTYFP:  3-character county FIPS code
• TRACTCE:  6-character census tract code
• POPULATION:  2010 Census population tabulated for the census tract
• LATITUDE:  latitude coordinate for the center of population for the census tract
• LONGITUDE:  longitude coordinate for the center of population for the census tract

#### Centers of Population by Block Group:  2010

State/state equivalent entity-based text files containing the mean centers of population for each census block group within a state/state equivalent entity for the 2010 Census. The record layout is:

• STATEFP:  2-character state FIPS code
• COUNTYFP:  3-character county FIPS code
• TRACTCE:  6-character census tract code
• BLKGRPCE:  1-character census block group code
• POPULATION:  2010 Census population tabulated for the block group
• LATITUDE:  latitude coordinate for the center of population for the block group
• LONGITUDE:  longitude coordinate for the center of population for the block group

### Centers of Population from Previous Censuses

[PDF] or denotes a file in Adobe’s Portable Document Format. To view the file, you will need the Adobe® Reader® available free from Adobe. The letters PPT indicate a document is in the Microsoft® PowerPoint® Format (PPT). To view the file, you will need the Microsoft® PowerPoint® Viewer available for free from Microsoft®. [an error occurred while processing this directive]
Source: U.S. Census Bureau | Geography | (301) 763-1128 |  Last Revised: February 09, 2015