This part introduction presents an overview of the key concepts discussed in the subsequent chapters. The part provides an overview of his work on the Great Plains and shows how a wide range of sources covering a large geographical area and a long period of time can be integrated to challenge existing orthodoxies. It investigates the spread of population through western Canada in the late nineteenth century. The part focuses on a wide range of work looking at agricultural change in a small area of south of England through the twentieth century. It explores British responses to overfishing and French responses to American cereal imports in the nineteenth century. The part illustrates the range of sources, approaches, and findings that GIS enables in the study of rural and environmental history.