The USGS Land Cover Institute (LCI)
Cropland by County Since 1850 and Population Since 1790
A Record of Settlement and Agricultural Disturbance to the Land
A time series data set of cropland and population proportions has been developed at the county level to provide data on land use conversion and rates of change. The U.S. Bureau of the Census and related agencies inventoried a county cropland series from 1850 to the present. "Improved farmland" acres were counted from 1850 to 1920 for every decade. Starting in 1925, cropland acres were counted. From 1790 to 1990, the Bureau of the Census counted population at the county level.
Spatial data were purchased from Louisiana State University. The data were merged and edited to match the Census data. Tabular data were obtained from the Inter-university Consortium for Political and Social Research and a variety of other sources, and missing data were keyed. Because sharing restrictions prevent distribution of the county decadal boundaries and substantial portions of the Census data, we calculated proportions of improved farmland/cropland and population into the modern county boundaries. The edited and altered data set is available for download.
The methodology is described by Waisanen and Bliss (2002). These data were assembled for the purpose of carbon modeling, but many other applications are possible.
The animation of the time series for improved farmland/cropland and population can be seen by clicking the following links: