Geography Main | Maps | TIGER | Reference
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Geography Main | Maps | TIGER | Reference |
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Please take a few moments to review this page before sending questions concerning the TIGER® Map Service and Gazetteer applications, Maps, ZIP Codes® and other U.S. Census Bureau geography. You will find the answers to most of the questions we receive here, or we provide links or suggestions of other places to look. The TIGER Map Service is an old, experimental system, based on the 1998 TIGER/Line® files and 1990 Census data. It DOES NOT REPRESENT the most recent address information available to the U.S. Census Bureau as a result of the 2000 DECENNIAL CENSUS.
Information about Census 2000 data is located at Your Gateway to Census 2000
As noted above, the TIGER Map Service was developed as an experiment in Web-based mapping. The Bureau's main effort now, in conjunction with private contractors, is in the development of a separate and more elaborate data delivery and mapping system called the American FactFinder. The Census Bureau has continued to maintain the TIGER Map Service because it has proved useful to the general public. It was never intended to be a robust all-purpose mapping system to meet the needs of high-volume government, business or other organizations' applications.
The Census Bureau will not commit to diverting its resources to subsidize the operations of others, no matter how worthy the goals of such an application. It was not intended as a substitute for agencies, businesses, or other organizations developing their own mapping applications. If you need a major map plotting application for your site you should develop your own software and hardware system to support it. Any application that uses our mapping service does so at the user's risk. The Census Bureau plans continue to try to maintain the TIGER Map Service for at least the near future at its current level, but we accept no obligation to provide special support (or timely repair) of the system so that it can meet some other governmental, commercial or organizational mission.
We cannot provide the TMS source code. The TIGER Map Service (TMS) was started
in 1995 as a "proof of concept" of a basic Web mapping application, and was not done with a view to providing the
public with Internet mapping software.
This application was developed by adapting an existing piece of mapping software to create maps on the Internet.
This test application was not completely documented as the Census Bureau never intended to disseminate it to the
public. As written, the software is hardware specific and some components of the uncompiled source code used to
generate the mapping engine have been lost.
There are several commercial map packages available now that can provide Internet map images. We suggest that you
look at some of these applications for models of this type of software. Top of page
We do not have historical census maps available online.
We do have paper copies of tract maps dating from the 1960 Census available
for purchase from our Jeffersonville, Indiana office at 812-288-3402.
The National Archives and Records Center also has
Census maps dating back to 1880. Although Federal census schedules date from 1790,
the preparation of Enumeration District maps did not occur until 1880.
These records,
prepared on a decennial basis, include maps of counties, cities, towns, and
unincorporated settlements, showing boundaries of the districts covered by the Census-takers (enumerators).
We do not have maps showing historical county boundaries.
We understand that there are sites on the Web with this information but we don't know how accurate their information is.
We do have some information on the land area
of various geographic areas. These data are based on the 1990 Census boundaries for these areas.
Note that some counties and places have had changes in boundaries since 1990. We do not plan to
update these data until we process the results of the Census 2000.
Top of page
The latitude and longitude we use comes from a data base that stores it in decimal degrees.
The formula for converting back and forth from the more traditional degrees, minutes, and seconds
format is given in TIGER FAQ 22. In
TIGER FAQ 23 we discuss the level of precision (implied vs. real) in our coordinates.
Use the U.S. Geological Survey's Geographic Names Information System (GNIS) to find the county that a place is in.
The Census Bureau does not have maps or digital files showing the boundaries of U.S. Postal Service ZIP Codes. The fact that ZIP Codes aren't required to be polygons makes them difficult to map. They are networks of streets served by mail carriers or just individual post offices and are a tool for mail delivery.
They also change periodically as required to meet Post Office operational needs.
Various companies have created maps by interpolating boundaries between occurrences of
ZIP Codes on the ground. However, this does not guarantee that the U.S. Postal Service delivery routes will follow this interpretation.
In the past, the Census Bureau produced the 1990 Gazetteer ZIP Code file and a 1999 ZIP Code file. These files were produced as byproducts of Census Bureau internal operations. They were not developed as a formal product. However, the Census Bureau has made them available to the public "as is". There will be no updated versions of these files.
The Census Bureau will not be producing data files containing U.S. Postal Service ZIP Codes either as part of the Census 2000 product series or as a post Census 2000 product. However, due to the public's interest in having statistics tabulated by ZIP Code, the Census Bureau has created a new statistical area called the ZIP Code Tabulation Area (ZCTA) for Census 2000. The ZCTAs were designed to overcome the operational difficulties of creating a well-defined ZIP Code area by using Census blocks (and the addresses found in them)
as the basis for the ZCTAs. For more information on the ZCTA delineation product and ZCTA-based products visit the ZCTATM Web page.
There is no correlation between U.S. Postal Service ZIP Codes and
U.S. Census Bureau geography. This is because individual U.S. Postal Service ZIP Codes can cross state, place, county, census tract, block group and census block boundaries (just to name a few). The geographic entities the Census Bureau uses to tabulate data by are relatively stable over time. For instance, census tracts are only defined every ten years. In contrast, U.S. Postal Service ZIP Codes are designed to meet the day-to-day operational needs of the U.S. Postal Service and tend to change more frequently than every ten years. Because of the ill-defined nature of ZIP Code boundaries, the Census Bureau does not have a file (crosswalk) showing the relationship between U.S. Census Bureau geography and U.S. Postal Service ZIP Codes.
ZIP Codes and Metropolitan Statistical Areas. We do not have any file that will relate Metropolitan Statistical Areas to U.S. Postal Service ZIP Codes.
ZIP Code Corrections. We cannot make ZIP Code corrections to our data sets based on e-mail messages.
We can use only information that we receive through our cooperative operations with the U.S. Postal Service.
Further, the Census Bureau does not offer "crosswalk" or "relationship" files that associate U.S. Postal Service ZIP Codes to any legal and statistical census geography. For the most accurate and up-to-date ZIP Code data, we suggest contacting the source for ZIP Code information: the United States Postal Service. Again, for more definitive information on U.S. Postal Service ZIP Codes, contact the U.S. Postal Service.
In some cases the Census Bureau will do special tabulations or research on a fee basis. For a specific
special tabulation request, send a message to pop@census.gov
for demographic statistics, or to econ@census.gov for economic statistics.
We do not provide information about, or the names of individual people or individual business establishments.
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City Data and Maps
We do not have a list of cities of the world with their locations. However, for information
about U.S. Metropolitan Areas, definitions and the component parts of each try the link to the
Metropolitan Areas page. For information on the
land area of various levels of geography try this
link. For a
ranking of cities by land area try this link.
For leads on other possible sites for foreign city information start at this URL: http://www.census.gov/geo/www/gis-gateway.html.
Another possibility is using one of the WWW search engines such as Yahoo or Alta Vista using the term "city". Top of page
Driving Directions
We do not give driving directions between points nor do we have bus or subway maps.
However, there are a number of commercial sites that do. Try looking for them with one of the
Web search engines using the key word "maps". Top of page
Gazetteer
This geographic place name look-up application was an early test program based on 1990 census data.
It was left on our web site because some people still find it useful. It is not advertised as,
nor does it represent the current list of incorporated places or Census Designated places in the United States.
Top of page
Genealogy
We cannot look up genealogical information or family histories. The only information we have about
this subject is on our Genealogy page. We cannot help you find relatives or
where individual people live now or where they lived in the past.Top of page
Glossary
See this page for a
Glossary of Census 2000 Geographic terms.
For detailed information on Census Bureau geographic terms and concepts see the
Geographic Areas Reference Manual. Top of page
Public Domain Maps
The Census TIGER data base is the source for maps generated by the TIGER Map Service. The data used to create the maps comes from the Census Bureau, an agency of the U.S. Government, and is in the public domain. Thus the maps you can download from this site are in the public domain
and you are free to use them as you choose. They are created on the fly and
displayed on the screen in a raster (or bit map) format.
They aren't meant to be imported into other mapping or GIS packages.
They can be imported into many graphics or paint packages where they can be further manipulated to a limited extent.
If you want the base data for use in your GIS or other mapping package visit our TIGER®
Page for information on the TIGER/Line® product. We also have some cartographic boundary files
accessible from this page. Top of page
Other Maps and Types of Information:
We do not have general purpose city, county or state maps. If you are looking for
general purpose maps for use as graphic images, try some of the commercial
clip art collections (some have both vector and raster images) or graphics design packages.
Some of the word processing software suites also have them. A good source for general purpose
paper and digital maps is the U.S. Geological Survey,
they are also the source of geological and land use maps. Also, try your state/local Department of Transportation.
For aeronautical and nautical charts try the National Ocean Service
Contour, general purpose, State and County, etc.
Elevation Data
Our data base does not contain topographic, elevation or
terrain information so we can't display contours.
We do not need this information for our work and, even though it might be useful to others, we
would not be permitted to expend the resources to add it. Try this link to the
U.S. Geological Survey
for information on Digital Elevation Models (DEM). Top of page
Property Line or Plat Maps
We do not have maps that show property lines
or that show ownership of property. Your local county/city assessment office is the
place to look. Top of page
Maps of other countries
We don't have maps of other countries. There is some population data
about other countries in the Population Area pages.
Another possible source of population data, current and historical, is the
CIESIN project, but they are not affiliated with the Census Bureau.
Top of page
Population and Economic Statistics
If you want demographic or other types of data follow these links for the latest
population or
housing statistics for various levels of geography
(state, metropolitan area, county, tract, etc.). Another area with population and economic data
at the state and county level is State and County QuickFacts. These links should answer most questions, if not, go to the Census Bureau's
Subjects A - Z page. Top of page
Town and City Locations
When you ask the system to place a map pin on a town's location it puts it at the approximate center of the
polygon formed by the legal boundaries as given to us by the state/local government. That means it could fall
away from the built up area or even in the middle of a body of water. Since there are close
to 50,000 places in the U.S. we don't have the resources to edit these locations manually to
put them in a more "logical" place.
ZIP Code Information
Special Research Requests
We are not funded to do free research or compile sets of statistics for people doing papers or
working on government contracts. We have the resources to put up much, but not all, of the Census Bureau's data
on the Internet (some free and some for a fee). Most of it can be found by following the links from the
Subjects A-Z page. If you have not been able to find the specific
information you need after searching our Web site or need more background information, contact us using one of the e-mail links provided.
Information about Census 2000 data is located at Your Gateway to Census 2000
Questions on Population statistics, contact - pop@census.gov
Questions on Income and Poverty, contact - hhes-info@census.gov
Questions on Economic and Business statistics, contact - econ@census.gov
Questions on TIGER/Line files, contact - tiger@census.gov
Questions on Maps and Boundary files, contact - tiger@census.gov
Questions on General Census Geography, contact - geography@geo.census.gov
Questions on TIGER Map Service, contact mapsurf@geo.census.gov
Questions on ZIP Codes, contact U.S. Postal Service
