Here's an excerpt from a post war letter written by Margedant to Rosecrans:
The Topographical Department of the Army of the Cumberland was the best organized and best equipped and most effective Topographical Department in the field. Considering the circumstances, time and urgent want of such a department, it may be safely said that it was a perfect one. We had representative engineer and surveyors with brigades, divisions and army corps and even with regiments and outposts. No scouting or reconnoitering party went out without its engineer; additions and corrections to our information maps had to be sent daily to our office at headquarters; We corrected, enlarged and combined our maps in accordance with such reports, and such information as we procured ourselves at the headquarters, through information of prisoners, scouts and our own personal reconnoitering. The revised information maps were then printed at night or in a special printing wagon, in the time of the march, and distributed by special messengers or through the usual channels of the army. Engineers and commanders of troops were thus constantly kept advised and ordered to make additions or corrections at once and report the same to headquarters. We often employed as high as thirty draftsmen; we had a large and full equipment of photographic apparatuses, among them solar cameras to enlarge views of rebel fortifications. We had two lithographic presses, and no doubt, you remember well our black field maps, printing and multiplying quickly the maps on the wagon in time of the march. We furnished every commander with the black maps and a bottle of potassium, which should be used same as ink, producing white lines. (You remember General, that this process was an invention of my own and that the so called "blueprint' of drawings and maps now so largely used, has sprung from them.)
You well remember the maps which we printed on the reversed side of neckties and handkerchiefs, yes, even on the reversed side of shirt-bossoms (sic) and sleeves, for the use of scouts and spies.
Most certainly, there was no department more serviceable and which had done more service than the Topographical Engineer Department of the Army of the Cumberland. The organization of a Topographical Dept. was not specified in the Army regulations. It was a creation of our own, brought to life by your orders and directions, and inspired by your personal influence. I said above, that there was no material change in the department when you left; we kept onward following the spirit of the founder.
If you like like we can move to the sanitary conditions of the AOTC I'm serious.
I know most of this is falling on deaf ears and blind eyes but someone needs to post it and maybe someone will read it and decide to read outside the box.