Richard Hantula & Joyce Hart 
Pennsylvania [PDF ebook] 
The Keystone State

Nicknamed the Keystone State for the pivotal role it played in colonial days, Pennsylvania has transformed itself from an industrial hub whose strength rested on coal mining and steel production to a state with a diversified economy that includes natural gas, manufacturing, agribusiness, tourism, and more. This book presents an engaging overview of the history, culture, people, and geography of Pennsylvania, from the urban centers of Philadelphia and Pittsburgh to the rolling farmland of Pennsylvania Dutch country to the Pocono and Allegheny Mountains.