One thing that many interpretation signs, museums, and books mention was how horrible maps of the Eastern portion of the United States at the time were, and the maps of the Gettysburg region were no different. What the generals at Gettysburg, and many others during the Civil War, relied upon during the Civil War for cartographic knowledge were topographical engineers. These officers were trained in cartography, physical geography, and military engineering. They knew how to survey an area, analyize the topography to discover the best places to position an army, and how to prepare defenses. General Meade himself was a topographical engineer and Lee used his own West Point geographical engineer skills to scout the land.
The United States Corps of Topographical Engineers, and then its merger partner, the United States Corps of Engineers, have trained geographers, many of which have majorly affected the field. The men and women of these corps have impacted the science of geography and the world via there efforts ranging from mapping the West and using that fame to run for president, to developing the first satellite map, to using old tourist photos to crowdsource map potential battlefields, to remarrying mathematics and geography. These are geographers who few know but have radically altered science and knowledge.
Fortunately for myself I am not the only person in awe of these topographical engineers. There is a society of living history reenactors who educate by reliving the glory days of the Corps of Topographical Engineers. These people, which I have zero affiliation with, dress up and act as topographic engineers and participate in educational activities. These reenactors live somesort of educating, Civil War, geography trinity of dreams I have.