MAPS and MAPMAKERS of the Civil War
It was hazardous work; the nearer to the enemy's lines I could penetrate, the more valuable were my field notes and the resulting maps. It was a business in which the lives of men counted as nothing against the chance of defining a road or sketching a bridge. Whole squadrons of cavalry escort had sometimes to be sent thundering against a powerful infantry outpost in order that the brief time between the charge and the inevitable retreat might be utilized in sounding a ford or determining the point of intersection of two roads.