At the intersection of the Allegheny, Monongahela and Ohio rivers, Pittsburgh set production records in the Second World War as a grimy steel town. With later shifts in its heavy manufacturing economy, Pittsburgh planned the first urbanredevelopment authority in the US; the Pittsburgh Renaissance became the most extensive peacetime reconstruction of an American historical urban center. The revitalized city has changed both civic identity and its economic foundations, stressing medicine and biotechnology research and development, education, banking and computer services, sports (baseball’s Pirates and football’s Steelers) and the arts, gaining renown as a highly habitable city of just over 300,000.