The social and demographic data included in this collection consist of a single data file for each decennial year between 1870 and 2000, covering 10 of the 12 Great Plains states. Information on a variety of social and demographic topics was gathered to historically characterize populations living in counties within the United States Great Plains, in terms of: (1) urban, rural, and total population, (2) vital statistics, (3) net migration, (4) age and sex, (5) nativity and ancestry, (6) education and literacy, (7) religion, (8) industry, and (9) housing and other characteristics. These data include selected material compiled as part of the United States population census. The United States Census of Population and Housing has been conducted since 1790 on a regular schedule that is decennial. The county-level social and demographic data produced by the United States government as a result constitute a consistent series of measures capturing changes in the United States population's size, composition, and other characteristics. A subset of the variables available from the short and long-form survey questionnaires of the United States Census of Population and Housing (as compiled for counties) were extracted from previously existing digital files. Besides the decennial census of the population, county-level data were drawn from an assortment of existing digital files as well as sources that were manually digitized. Other data include compilations of county-level information gathered from various federal agencies and private organizations as well as the agriculture and economic censuses. Supplementing these compilations are manually digitized consumer market data, religious data, and vital statistics, including information about births, deaths, marriage, and divorce.
Data drawn from the Consumer Market Data Handbook, the Census of Religious Bodies, the Survey of Church Membership, and Vital Statistics of the United States are not collected from a sample. Details of data collection procedures for religion and vital statistics information are available from the American Religion Data Archive and the United States Department of Health and Human Services [Report (PHS) 97-1003, 1997].
However, the United States Census of Population and Housing does collect some information from samples of persons and housing units. With the universe of all persons and housing units in the United States, the following summarizes the sampling methodology used in the United States Population Census from 1870 to 2000 (United States Department of Commerce, April 2002):
Sampling for the 1870-1930 United States Censuses
No sampling information was available for the years 1870 to 1930. Data represent 100 percent counts of the United States population.
Sampling for the 1940 United States
Census
The person was the sampling unit in 1940. The sample data collected information from 5 percent of the population.
Sampling for the 1950 United
States Census
The person was the sampling unit in 1950. The sample data collected population and housing information for 20 percent of the population.
Sampling for the 1960 United States
Census
The sample data population questions were asked of 25 percent of the population. For the housing sample data, some questions were asked of 5 percent of the population, some of 20 percent, and some of both (constituting a 25 percent sample for those questions).
Sampling for the
1970 United States Census
The housing unit was the sampling unit. For the sample data, some questions were asked of 5 percent of the population, some of 15 percent, and some of both (constituting a 20 percent sample for those questions).
Sampling for the 1980 United States
Census
For the STF3, one-half of all housing units and persons in group quarters in incorporated places of less than 2,500 persons were included in the sample. In all other places, one-sixth of the housing units or persons in group quarters were sampled. When both sampling rates were taken into account, approximately 19 percent of the nation's housing units were included in the census sample.
Sampling for the
1990 United States Census
A sample of persons and housing units was asked more detailed questions about such items as income, occupation, and housing costs in addition to the basic demographic and housing information. The primary sampling unit for the 1990 census was the housing unit, including all occupants. For persons living in group quarters, the sampling unit was the person. Housing units in governmental units with a precensus (1988) estimated population of fewer than 2,500 persons were sampled at 1-in-2. Housing units in census tracts and block numbering areas (BNAs) with a precensus count below 2,000 housing units were sampled at 1-in-6 for those portions not in small governmental units (governmental units with a population less than 2,500). Housing units within census tracts and BNAs with 2,000 or more housing units were sampled at 1-in-8 for those portions not in small governmental units. Persons in group quarters were sampled at a 1-in-6 rate.
Sampling for the 2000 United States
Census
Every person and housing unit in the United States was asked basic demographic and housing questions, for example, race, age, relationship to householder, housing unit vacancy status, and housing unit tenure. A sample of these people and housing units was asked more detailed questions about items such as income, occupation, and housing costs. The sampling unit for Census 2000 was the housing unit, including all occupants. There were four different housing unit sampling rates: 1-in-8, 1-in-6, 1-in-4, and 1-in-2 (designed for an overall average of about 1-in-6). The Census Bureau assigned these varying rates based on precensus occupied housing unit estimates of various geographic and statistical entities, such as incorporated places and interim census tracts. For people living in group quarters or enumerated at long-form eligible service sites (shelters and soup kitchens), the sampling unit was the person, and the sampling rate was 1-in-6.