Part 1: An American Offensive
Next: Sumter's First Target
The battle of Williamson's Plantation was a disaster for the British, not because of the British losses that were incurred, but rather because it cooled Loyalist ardor, greatly encouraged the Americans, and put to an end the previously-effective Provincial/Loyalist raids from Rocky Mount.
The most striking sign of this change in fortunes consisted of the defection of a body of Loyalist militia to the Americans. British Lieutenant-Colonel Banastre Tarleton lamented that:
"An instance of treachery which took place about this time, ruined all confidence between the regulars and the militia: The inhabitants in the districts of the rivers Ennoree and Tyger had been enrolled since the siege of Charles town, under the orders of Colonel [Matthew] Floyd; Colonel [Andrew] Neale, the former commanding officer, having fled out of the province for his violent persecution of the loyalists. One [James] Lisle, who had belonged to the same corps, and who had been banished to the islands, availing himself of the proclamation to exchange his parole for a certificate of his being a good citizen, was made second in command: And as soon as the battalion was completed with arms and ammunition, he carried it off to Colonel Neale, who had joined Colonel Sumpter's command on the Catawba."
Also boosting American morale was the assemblage of a new American army in the South under the command of Major-General Horatio Gates and seconded by Major-General Johann de Kalb. This army consisted primarily of a division of Maryland and Delaware Continentals, backed up by large numbers of Virginia and North Carolina militia. Their mission was to liberate British-occupied South Carolina.
Brigadier-General Thomas Sumter, who commanded a brigade of militia based in the Catawba Nation, intended to loosely cooperate with this American army. Writing to de Kalb shortly after the action at Williamson's Plantation, Sumter boasted that:
"I having Collected a party of men, attacked and Dispersed the enemy, So As to Cleare two Regiments of them [see Note 1]."
For all this bravado, however, Sumter remained deeply concerned about the numbers of South Carolina militia potentially in British employment. He wrote that if the British "have an opportunity of Collecting the Tories and imbodying the militia, who they Compell to do Duty... they will... add above ten thousand men to their army—and thereby be come so strong as Not only to Keep possession of Charles Town, but also a Great part of the State besides."
Sumter advised de Kalb that the main American army should send "a Body of Light Troops" to sweep down the eastern portion of the state and "take post upon the South Side of Santee River, at Neilson's and Marigalutes Ferries." In this position they "woud effectually Cut of their [the British] Retreat to Towns [i.e., the eastern seaboard] and thereby prevent them from forcing the Militia to retreat with them, or from there Gethering to gether the Forces, and also from Striping the Country of all its Resources." Sumter believed that in one fell swoop, the British would be forced to abandon all of their posts in the BackCountry. Sumter's proposed advance would have been dangerous to the British, but such a force would have had numerous rivers to cross and could have been easily delayed. What's more, as the Americans advanced deep into British-held territory, they would themselves run the risk of being cut off and destroyed. Gates and de Kalb would ultimately adopt a much more conservative (and in my view, sensible) strategy.
Sumter had no intention of adding his numbers to the main American army, but rather saw their offensive as an opportunity when he might "be the better inabled to act aGainst the enemy With a probability of success."
Rocky Mount and Vicinity, July, 1780 (click to enlarge). 1) British post at Rocky Mount, 2) British post at Hanging Rock Creek, 3) site of the battle of Williamson's Plantation, 4) British post at Camden. Shaded area is the Catawba Nation. The dark line at the top of the map is part of the border between North and South Carolina.
1. Sumter is referring to the regiments of Ferguson and Floyd, which were routed at Willamson's Plantation.
Marg Baskin's Banastre Tarleton website has a transcription of Tarleton's postwar memoir.
Thomas Sumter. Letter to Johann De Kalb, July 17, 1780. Colonial and State Records of North Carolina.