University of Iowa historian Colin Gordon is the author of Mapping Decline: St. Louis and the Fate of the American City: a book that investigates how Saint Louis changed during the twentieth century. In his research, Gordon utilized archival records as well as GIS techniques. He also created this series of four interactive maps as a companion to this book. Each of these maps illustrates a different phenomenon that shaped Saint Louis: white flight; laws and policies that deliberately created racial segregation; municipal zoning laws; and laws and policies that fit under the umbrella of "urban renewal." Each of these four maps includes a timeline accompanied by a short explanation, which allows visitors to learn how certain policies and laws impacted demographic trends. This website may especially appeal to educators of U.S. history, legal history, and urban studies.