"A City Transformed" is available to read online (for free!) at Google Books:
here
The summary page is here: http://books.google.com/books?id=f891HxR6y9MC
Written by Franklin and Marshall professor David Schuyler, this book provides a detailed narrative of the failed "Urban Renewal" project in mid-20th century Lancaster City. It spells out the reasons behind "Urban Renewal", how it came about, and examines how and why it failed.
This book is most highly recommended reading.