One interesting set of artifacts from the Official Records pertaining to events 150 years ago today (May 5) is a couple of maps added to correspondence between officers in the Army of the Potomac. There are actually several of these, but let me focus on two in particular.
First there is this message from Major-General Winfield S. Hancock, commanding Second Corps. Hancock sent this message to army headquarters around mid-day:
Hdqrs. Second Corps, Army of the Potomac,
May 5, 1864.
The infantry of this corps hold the intersection of the Brock road with road from Furnace. Two small scouting parties of cavalry have connected with my left to-day, but none have been seen on the Brock road. A company 100 strong (infantry) just went out on a crossroad leading to Catharpin road from Brock’s and encountered about three-quarters of a mile out 1,000 enemy’s cavalry in three lines and one battery. This cavalry may have been a mask. It was near the intersection of roads, as shown on the inclosed sketch. Two companies of infantry are out on the Brock road, but have met nothing. The enemy do not appear yet in force on the plank road. The skirmish line has advanced, say, three-quarters of a mile without strong resistance. Some men wounded. The line is still being pushed out.
Winf’d S. Hancock,
With that message was this diagram:
Notice the annotation to the right – “A” marked the spot where the Confederates were entrenched.
Later in the afternoon, Lieutenant-Colonel Theodore Lyman, aide-de-camp from Army Headquarters assigned to facilitate communications with Second Corps, provided an update on the situation:
Headquarters Second Corps,
May 5, 1864–5.05 p.m.
Headquarters Army of the Potomac:
General: There is a general attack as per diagram. It holds in some places, but is forced back to the Brock road on the left. Gibbon <ar68_411> is just coming up to go in, and Barlow is to try a diversion on the left; a prisoner of Archer’s (Tennessee) division says he was told that Longstreet was to-day on their right.
Lieutenant-Colonel, Volunteer Aide-de-Camp.
And he attached this diagram:
Now there’s a lot of context here I’m leaving out. The tactical situation in the Wilderness; the limited communications between commanders; friction between commanders; and just plain old confusion. I cannot possibly due justice to the events occurring between noon and 5:05 pm, May 5, 1864 in a single blog post. (And there are plenty of authors who have done a far better job of it than I could ever attempt.)
But my point with these two artifacts is to highlight just how the officers directing this battle were conveying information. They were using crude graphic displays. Simple sketch maps. Did those get the point across? In a rough way, yes.
Fast forward about 100 years. In the 20th century the U.S. Army benefited from topographical maps based on detailed surveys – often using aerial photography. Often these maps were laminated for use in the field. But for communicating the status between commands, the preferred way was an acetate overlay. Something like this:
Notice the cross hairs on the upper left and the lower right. Those referenced the grid lines on the map, to allow the acetate overlay to mach up with the map. For higher security, those were often not labeled. The separate coordinating instructions carried a list of reference points used for overlays in that particular operation. But that aside, you get the picture (I hope). Similar crude sketch, but with a fine detailed topographical map to back up the situational diagram.
Looking at the 21st century – or to be more precise, stating in the 1990s – the U.S. Army turned increasingly to computer systems in order to relate these tactical and operational diagrams. And with that came the ability to visualize the battlefield real-time. One example is Blue Force Tracker. That system uses a myriad of devices and relies on a robust data network.
I could tell you more about Blue Force Tracker, but it would probably bore you to death…. (and if you were still alive after that, I’d probably have to kill you due to security concerns….). But consider a screen shot from one of the component applications deployed as part of the Blue Force Tracker system:
The map, in this case of Baghdad, showing the location of friendly units. This being derived from automatic input, manual entry, and other sources on the vehicles and command centers.
Is it accurate? Um… it is only as good as the data fed into it.
Were Hancock’s or Lyman’s diagrams accurate? Well as accurate as the men putting pencil to paper could make them. Be it on paper or by computer, the diagram helped relate to others what the situation “looked” like on the firing line.
(Citations and Civil War illustrations from OR, Series I, Volume 36, Part II, Serial 68, pages 408 and 410-11.)