While many Civil War reference books exist, there is no single compendium that contains important details about the combatant states (and territories) that Civil War researchers can readily access for their work. People looking for information about the organizations, activities, economies, demographics, and prominent personalities of Civil War states and state governments must assemble data from a variety of sources, with many key sources remaining unavailable online. This volume provides a crucial reference book for Civil War scholars and historians, professional or amateur, seeking information about Pennsylvania during the war. Its principal sources include the Official Records, state adjutant general reports, legislative journals, state and federal legislation, executive speeches and proclamations on the federal and state levels, and the general and special orders issued by the military authorities of both governments, North and South. Designed and organized for easy use, this book can be read in two ways: by individual state, with each chapter offering a stand-alone history of an individual state’s war years; or across states, comparing reactions to the same event or solutions to the same problems.