This part introduction presents an overview of the key concepts discussed in the subsequent chapters. The part explores how GIS's central attribute, locating an array of data at a point, can be used to repopulate a nineteenth-century land ownership map that originally excluded African-Americans, creating a more representative display of the actual residential population. It utilizes census data at the village level to examine landscape and soil patterns that were associated with different levels of social stratification during the volatile period following World War I. The part explores the Federal government's Home Owners' Loan Corporation which gathered the four color risk maps produced by local realators in every major American city for the information of all investors, re-enforcing the segregation of real estate in American cities and furthering the decline of those identified with the scarlet letter.