final examination of troop movements prior to and after the battle of guilford courthouse

8/8/2019 Final Examination of Troop Movements Prior to and After the Battle of Guilford Courthouse

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Final Examination of Troop Movements Prior To and After the Battle of Guilford

Courthouse, March 15, 1781.

GIS Project for Geol 340

Professor Dave Dobson

By

AnneMarie Dickey


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My GIS project revolves around the resolution of how the Continental and British Armies

moved with respect to one another in the weeks leading up to the Battle of Guilford

Courthouse on March 15, 1781. The primary data sets were two maps supplied by the National

Park service that show period roads, various structures and cultural features as well as the lines

of march for both armies. The maps are highly cluttered with information, with much of it

being homestead information of little interest or relevance to the primary ostensible purpose of

the maps which is to show who did what both before and after the battle. Since both armies

used the same roads and crossed back and forth a number of times, it is extremely difficult to

determine which army is which or exactly what day the army may have marched over any given

place.

The first order of business was to take both maps to a commercial printer and then have

the maps digitized into a raster format that could be geo-referenced to a current map of North

Carolina.


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A difficult feature was that one map was surveyed in Northings and Eastings, which is a

simple Cartesian coordinate system, but also unrelated to many current map projections. A

significant degree of help was needed to properly geo-reference this map. The second map

was far more straightforward and was based on standard latitude and longitude coordinates

that were quickly tied to known points on the North Carolina map.

With the maps now located as a raster overlay, it was possible to begin making

additional layers of detail. First, major cultural features such as churches, towns, forts, mills,

taverns and militia muster grounds that existed in 1781 were all collated into two shape files

(one for each map). Next, the road systems for each map were plotted with additional shape

files. It quickly became obvious that the road grids for both maps do not match up, either due

to chronological discrepancy or period map uncertainties.

{Note: Road grid for lower map with buildings and some troop movements of the Continental Army plotted.}


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After the two road files were complete, I then began to sort out the day by day

movement of each army. This was often confusing, since both armies used the same roads and

often went over the same area several times. I broke down each day of movement for each

army into separate shape files which I could then assemble into layers as I desired. This was

repeated for campsites as well.

{Movement of the Continental Army (green line on right side), March 1, 1781.}

When the entirety of the troop movements had been plotted in shape files, I began to

assemble layers of daily activity where it would possible to see simultaneous movement. This

starts on the 6th

of March when General Cornwallis attempts a lunge from the east at the


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Continental Army. General Greene is obliged to flee north into modern Randolph County as

colonial militia fight a rear guard action.

Over the next few days, both armies attempt to ascertain the position of each other

while seeking to bring about a decisive battle on their own respective terms. Cornwallis wanted

to destroy Greenes force in a surprise engagement before he could get reinforcements while

Greene wanted to wait until additional forces arrive and then fight on ground of his choosing.

This interplay between the two commanders is captured by the additional of each daily layer of

movement that leads up to the climactic Battle of Guilford Courthouse on the 15th

of March.

Here, Greene can be seen moving to the Courthouse on March 14th

(blue). Cornwallis

(green) moves from the south on the morning of the 15th

and ultimately takes the field (a


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textbook example of a Pyrrhic victory as he takes devastating losses) as Greene withdraws the

army north to the Speedwell Iron Works with the armys baggage train.

Over the next few days, the gravity of Cornwallis losses at Guilford Courthouse and his

inability to resupply force him to withdraw towards Wilmington, which begins the final months

of the Revolutionary War leading to his surrender at Yorktown. Greene, sensing weakness,

pursues Cornwallis shortly thereafter.

{Cornwallis (purple) retreating from Guilford Courthouse as Greene (blue) decamps from the Iron works

north of the courthouse and pursues.}

The construction of daily layers has made interpretation of movement far more

accessible for both casual and academic observations. This is a time period where dragoons

(light cavalry) where the primary battlefield intelligence/ reconnaissance tool, and the degree


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of uncertainty that both armies have with respect to one anothers actual position is manifest.

While Cornwallis finds a convenient crossroads south of the courthouse to menace Greene and

restrict the movement of the Continental Army, he is making an educated guess. It is obvious

at points that neither force knows where the other is, or at least cannot do anything about it

even it the information is available. I will be submitting this project, with additional layers of

requested information to the National Park Service and I hope that future visitors to Guilford

Courthouse National Military Park will find it useful.

final examination of troop movements prior to and after the battle of guilford courthouse

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