The Gettysburg Campaign was the first campaign in American history where the Signal Corps provided the army commander communications with all of his corps commanders. The Signal Corps provided communications and intelligence during the entire campaign by operating a complex system of fixed and mobile flag signal and observation stations. This book is a comprehensive self-guide of the Signal Corps involvement in the Gettysburg Campaign. It utilizes the format and methodology of the series of battlefield guides developed for the U.S. Army War College by Dr. Jay Luvaas and COL Harold Nelson. The user of this guide will tour the key locations utilized by the signalmen and learn about the action directly from the participants by reading from their individual reports, letters, and diaries. This guide has been developed specifically for company grade signal officers as a tool for their professional development. It is intended to increase regimental affiliation and instill a sense of pride, the heritage of the Signal Corps by demonstrating the difficulties which faced our predecessors and how they overcame them.