Consider three letters written shortly after the battle: North Carolina governor Abner Nash to Virginia governor Thomas Jefferson on June 25, James Monroe to Thomas Jefferson on June 26, and Major-General Johann de Kalb to General George Washington on June 29.
Nash and Monroe referred to a brigade of North Carolina militia commanded by Brigadier-General Griffith Rutherford, but provided no hint that some of Rutherford’s men have won a victory at Ramsour’s Mill. In fact, their letters do not even suggest that there was significant Loyalist opposition in that part of the state. The letter by de Kalb is the only one of the three to refer to a Loyalist threat: he mentioned to Washington that a detachment of his men were in Guilford County helping the local militia defend themselves against their Loyalist counterparts. It’s unclear whether de Kalb was even aware of Rutherford’s force. Although he complained that “I am quite in the dark as to all eternal News from the South as well as from the East,” Rutherford’s force to the west was missing from a report he gave of American forces in the state.
Nash, Monroe, and de Kalb agreed on one thing: the main problem facing the Americans was a lack of provisions. Monroe noted that because of a lack of provisions, “…the Army under General de Kalb at Hillsboro, and that under General Caswell here [Cross Creek], are no longer able to hold those Stations and are in that dilemma, that they have only the alternative of advancing shortly on the Enemy or retiring to Virginia.” De Kalb complained that “We live from hand to mouth, and get very little, but what is collected by Detachments, and brought in with our Baggage Waggons [from] the Scatter’d few farms in this part…” As a consequence he was forced to put his men on reduced rations. [for a map of American dispositions, see here].
Perhaps the earliest written record of the battle of Ramsour’s Mill appears in the journal of Anthony Allaire, a lieutenant with the American Volunteers. On June 23 (i.e., 3 days afterwards), he wrote:
“Lay in the field at Ninety-Six [South Carolina]. Some friends came in, four were wounded. The militia had embodied at Tuckasegie [Tuckasegee], on the South Fork of Catawba river-were attacked by a party of Rebels, under command of Gen. [Griffith] Rutherford. The [Loyalist] militia were scant of ammunition, which obliged them to retreat. They were obliged to swim the river at a mill dam. The Rebels fired on them and killed thirty. Col. [Patrick] Ferguson, with forty American Volunteers, pushed with all speed in pursuit of the Rebels. It is seventy miles distance from Ninety-Six. The militia are flocking to him [i.e., Ferguson] from all parts of the country.”
It was not until July that American authorities referred to the victory in their correspondence. In a July 4 letter, South Carolina militia Colonel James Williams wrote that the Loyalists had 1,300 men at Ramsour’s Mill, that 35 were killed, and that 500 horses and all of their baggage had been taken. On July 23, North Carolina militia Major Thomas Blount claimed that the Loyalists had 70 men killed, 100 taken prisoners, and lost 300 horses and all of their baggage. Blount also claimed that the Americans lost a mere 7 killed and 19 wounded.
On the British side, Lieutenant-General Charles Cornwallis, did not refer to the battle in his correspondence with London until August 20, when he wrote:
“[O]ur Friends in Tryon County, North Carolina, in the latter end of June, who, having assembled without concert, plan, or proper leaders, were, two days, after, surprised and totally routed by the Son of Genl. Rutherford. Many of them fled into this Province, where their reports tended much to terrify our friends and encourage our enemies.”
Cornwallis perhaps chose to withhold this information until he could also report on positive developments. In this case, news of the defeat in North Carolina was accompanied by news of the British victories at Camden and Fishing Creek.
Note: Of course one's conclusions depend on the sources. In this case I searched the Colonial and State Records of North Carolina, the Thomas Jefferson papers, the George Washington papers, and the records of the Continental Congress. Additional mentions of the battle may have been found were I able to search newspaper articles from that time.