Purposes of the Census and its Geography
- "... provide the most complete and accurate population count possible for apportionment ..."
- Redistricting for congressional and legislative purposes.
- Track economic and social trends.
- Distribution of public funds.
- Administration of public and private programs
- FAQ's about Census Geography
Categories for Census Geography
- Legal - Nation, States
- Administrative - School districts, zip codes
- Statistical - Regions, MSA's
- Glossary for Census Geography
When did it start
- Counties are an English tradition
- First census - 1790
- Small geography areas based on population, topography and housing first appeared in 1890.
- Census Office
- Sanitary districts
- Create a network of these small geographic areas around the country
History of Census Tracts
- 1906 - Walter Laidlaw and the Population Reseach Bureau of the New York Federation of Churches
- 1909 - Laidlaw made his proposal to the Census Office
- 1910 - Census Office designated 8 cities with delineated districts
- Laidlaw divided New York City into districts
- The data would be available for purchase!
More History of Census Tracts
- The Census Office collected delineated data for these cities in 1910 and 1920.
- Only New York City used the data immediately.
- Mid 1920's - Chicago and Cleveland purchased their data and published it.
- 1929 - 18 cities reviewed or delineated new tracts for 1930.
A Little More History
- Howard Whipple Green
- Statistical consultant, Cleveland, OH
- American Statistical Association
- Committee on Census Enumeration Areas
- 1940 - Census Bureau officially adopted the census tract
- 1955 - Howard W. Green retired and the Census Bureau controlled promotion and coordination.
Importance of Census Geography
- Census Geography nests
- The geography does not cross established boundaries
- Block Numbering Areas (BNA's) covered areas without tracts
- BNA's became statistically equivalent to tracts with the 1990 Census
- Tracts became universal within the U.S. only with the 2000 Census
ZIP Code Geography
- ZIP code geography is separate from Census geography
- The U.S. Postal Service (USPS) created and control these boundaries
- They do not follow the same conventions as Census geography
- Cross legal, administrative and statistical boundaries
- Are not always completely enclosed
- Census Bureau created 1990 and 1999 ZIP code files on an "as is" basis
ZCTA's
- ZCTA's - ZIP Code Tabulation Areas
- Created by the Census Bureau
- Similar to ZIP Code boundaries but not an exact match
- File updated to 2002
- No further updates planned until the 2010 Census.
Other Resources for Census Geography
- Census 2010 Geographic Terms & Concepts
- Census Bureau Map Products
- U. S. Census Gazetteer Files
- Files the Census Bureau created to help people locate places without knowing longitude and latitude.
- Separate files for Places, Counties, County Subdivisions, Census Tracts and ZCTA's.
- Each record in the file contains FIPS numbers, latitude and longitude, area in square miles and meters, total population and total housing units.
- The files are in ASCII text format.
Sources: United States. Bureau of the Census. http://www.census.gov/geo/www/reference.html . Updated on May 24, 2016.
American Factfinder. http://factfinder.census.gov/faces/nav/jst/pages/index.xhtml . Updated on May 24, 2016.