What was the most immediate result of increased settlement of the Great Plains during the mid-to late 1800s

While we make use of many varieties of data, our primary sources come from county tabulations drawn from the U. S. censuses of population and agriculture. We have collected those data for the decennial population censuses from 1880 through 2000, as well as for the agricultural censuses (which were decennial until 1920 and then more frequent thereafter) from 1880 through 1997.3 In addition to census-based sources, we have collected other county-level tabulations of social characteristics. We use the population and social indicators data to understand population structure and change, and the agricultural census data to understand agricultural land use. Their consistency, as well as the effectiveness and long-term quality of the U. S. census, have made this part of our project straightforward. Some of these data were available to us in digital form, and others we collected in print form and then hand-keyed into our database. All of these data are described in Gutmann et al. (1998). Since that document was published, we have added data from recent censuses (1997 agriculture and 2000 population), while maintaining their content and structure. Although our study area is not coterminous with the 10 states, we have collected data that covered the entire area of the 10 Great Plains states, and often neighboring states, especially Iowa and Minnesota.