GEOG 594A
Culminating Experiences in Geospatial Intelligence

United States Data Sources

There are a large number of agencies, bureaus, and offices from which you can find data produced by the United States government. Many of the data suppliers make great efforts to supply and keep up-to-date the data they provide.

Searching for government information in the United States can sometimes be confusing and difficult to find. If you use what is called the agency approach, finding information can be a much easier process. When you are faced with a question about where to find data within the U.S. government, the first question you should ask yourself is "which agency or department is most likely to produce this information?" If it is environmental data, it would most likely be the EPA; if it is housing information, it could be either Housing and Urban Development or Census Bureau; if education data, then it would be the Department of Education. This provides you with an access point in finding the data instead of running random searches in search engines or library catalogs and coming up with irrelevant results.

While the website for each agency, bureau, or organization is different in each case, there are some elements that are useful to researchers that will always be the same. There will always be an "about" section that should be reviewed if you are unfamiliar with the type of information and data produced by that agency. There will also be a section of the website where publications or data are made available and this is typically where you will find what you need. Some agencies and departments make it easy for you to locate the information you need, and some websites are a little more challenging. Do not get discouraged if you are having difficulty finding the information you need, you can either contact the agency directly or contact your local librarian - both will provide the help you seek.

United States Census Bureau

Demographic data is usually collected by national census or by some other national-level survey, such as the American Community Survey conducted by the U.S. Census Bureau. The U.S. Census Bureau is the main collector and provider of demographic data in the United States. The Census Bureau collects this data in two main ways: the Decennial Census and the American Community Survey. The Decennial Census has been taking a census every ten years since 1790. This first census was short and consisted of the following questions:

The number of each of the following in every household:

  • Free White males of 16 years and upward (to assess the country's industrial and military potential)
  • Free White males under 16 years
  • Free White females
  • All other free persons
  • Slaves

The questions changed over time, and the amount of data the Census Bureau collects on modern census questionnaires allows for detailed analysis of the population in the United States.

Recognizing that the population changes dramatically in the ten years between each decennial census, the Census Bureau established the American Community Survey in 2005. In 2009, it is very difficult to make a reliable map based on the statistics collected in 2000, so the American Community Survey collects data on a yearly basis for a select sample of the population in efforts to provide more up-to-date demographic data for the United States. It should be understood that, like some parts of the census, this is sample data only and should not be treated as an absolute.

To access the data from either a Decennial Census or from the American Community Survey, you would use the American FactFinder on the U.S. Census website.

Here is an activity for you to familiarize yourself with using the American FactFinder:

  1. Point your browser to The U.S. Census Bureau
  2. Choose American FactFinder from the menu on the left.
  3. Choose 'get data' under the Decennial Census.
  4. Using detailed tables from Summary File 3 (SF3) and following the steps find the population for Camden, NJ by race. Do
    the same using the American Community Survey using 2007 data
  5. Compare the data.

Note that there was a population change for both whites and blacks in Camden, NJ, over the seven-year period. While this is not a significant increase in population overall, for what has often been called the poorest city in the United States, any change in population can be significant. This data can also be used to make some assumptions about where the people are moving by looking at some factors in the city of Philadelphia, right across the river from Camden.

To do this, let us take a look at housing price changes in Philadelphia over this seven-year period.

  1. Go back to American FactFinder.
  2. Using the same data sets find the median home value for Philadelphia, PA.
  3. When you are at the screen to choose a data table, use the subject search tab and scroll through the subjects to find median home value for occupied units.
  4. Again, compare the data.

Through this process of data comparison, you will start to get an overall picture of what is happening socially in different areas of the country and the world (if you are using international data). This exercise is valuable not only because you become more familiar with using the Census Bureau website but because you start to think about different variables that could possibly be affecting demographic data shifts over time. The data sets you worked with are just a part of all the data available via the Census Bureau, so you are encouraged to look around and experiment with making tables, maps, and downloading the data.

Environmental Data

Another rich resource from the United States Government is the Environmental Protection Agency. The EPA collects many different types of data regarding the environment; most often data retrieved from the EPA has to do with emissions and environmental atrocities conducted by large industrial corporations. While this information is available from the EPA and they have a gleaming new website design, this is one of the instances where finding the data on the agency's website is somewhat challenging.

The EPA has an interesting data tool called the Envirofacts Data Warehouse. In this data warehouse, you can find data on waste, water, toxins, air, land, radiation, and compliance and also make some maps of your local area displaying data found within the warehouse.

For this activity there will be little guidance; it will teach you to work through a website to find the data you need.

  1. From the EPA website, find the Envirofacts Data Warehouse. DO NOT search Google for it.
  2. Make a map of your local area showing all of the possible hazards.
  3. Pick the most frequent hazard and describe what the data is showing - for example, what does the little green square for Hazardous waste really mean?
  4. To save your map, right click on the image and save it as an image.
  5. To save the legend, click on the legend tab to the right of the map and right click to save it as an image.