Welcome to Pennsylvania, the Keystone State Students will explore the Appalachian Mountains, attend a Philadelphia Eagles football game, discover history at Valley Forge National Historical Park, and more as they learn about Pennsylvania's history, plants and animals, industries, sports, cities, famous people, and more in this fun, fact-filled title. Aligned to Common Core Standards and correlated to state standards. Abdo & Daughters is an imprint of Abdo Publishing, a division of ABDO.