Efforts to address the problems of distressed urban neighborhoods stretch back to the 1800s, but until relatively recently, data played little role in forming policy. It wasn't until the early 1990s that all of the factors necessary for rigorous, multifaceted analysis of neighborhood conditions--automated government records, geospatial information systems, and local organizations that could leverage both--converged. Strengthening Communities documents that convergence and details its progress, plotting the ways data are improving local governance in America.