The “Illinois Landcover in the Early 1800s” dataset was created by the Illinois Natural History Survey (INHS). The INHS is a division of the Prairie Research Institute at the University of Illinois Urbana-Champaign, dedicated to the study and preservation of the state’s biological resources.

The dataset is based on original surveys conducted by the General Land Office (GLO) between 1804 and 1843. Surveyors documented various landscape features in field notebooks and plat maps, noting details such as tree types, landscape quality, watercourses, and other notable features. These records are among the earliest detailed maps of Illinois, predating county land ownership maps and atlases.

The dataset was compiled to provide a detailed representation of Illinois’s landscape prior to extensive settlement. By digitizing historical GLO maps and notes, the INHS aimed to create a comprehensive land cover map reflecting the state’s early 1800s environment.

This dataset serves as a valuable resource for researchers, historians, and environmental scientists interested in analyzing historical land cover and ecological conditions, studying changes in vegetation and land use over time, and informing conservation and restoration projects by providing a historical baseline.

The dataset is available in Geographic Information System (GIS) formats, specifically ESRI Arc/Info, facilitating spatial analysis and mapping.

The dataset includes 42 land cover categories, such as prairies, forests, wetlands, and various landforms. These categories are based on the original terminology used by GLO surveyors. The attribute table contains items like “Land_Code” for detailed categories and “Map” for broader classifications.

The INHS digitized the original GLO maps by scanning microfilm copies, georectifying the images against USGS topographic maps, and tracing the line work using GIS software. They standardized and combined certain land cover names that varied by region or surveyor. For example, terms like “bluff” and “sand bluff” were merged.

As a scientific organization, the INHS aimed to preserve and interpret historical ecological data. Their focus on accuracy and standardization likely influenced the meticulous digitization and categorization processes, ensuring the dataset’s reliability for research purposes.

This dataset can be utilized for historical ecological research to understand pre-settlement environments, comparative studies of land use changes over time, guiding ecological restoration efforts by providing historical reference points, and educational purposes to illustrate Illinois’s natural history.

By offering a window into Illinois’s past landscapes, this dataset is instrumental in both academic research and practical conservation planning.