Referenced in the volume 'Journals of the Military Expedition of Major General John Sullivan' there are several references to and biography of Col. John Harper. John commanded a group of volunteers during the Sullivan campaign. This was a punitive raid consisting of over 4,500 men called for by General Washington to push the Iriquois siding with the British out of there traditional homeland. John's part in this expedition was sited in several Journals kept by officers. Specifically the Journals of George Grant, John Hardenbergh, John Jenkins, and in Major General John Sullivan's final Official Report of the Expedition.

John's volunteers were made part of the Fourth Brigade under James Clinton where John served as a Captain of the volunteers.
N.B. It was not unusual during the war to have persons serve at various levels on different missions. When referred to, however, protocol dictated calling the person at the highest rank attained.

John's specific role involved a force march of his men to destroy a town of 18 houses at the called variously, Skoi-yase, Schoyere and Scawtace or Long Falls. The official report states that "... at the same time a number of volunteers under Colonel Harper made a forced march towards Cayuga Lake and destroyed Schoyere while the residue of the army were employed in destroying the corn at Kanadesega of which there was a large auantity." Skoi-yase was identified as an important town located on the north bank of Seneca river at the present site of Waterloo, in Seneca County, New York. In fact, the town had been abandonded, but the houses were destroyed on September 8, 1779. On the return, another contingent was sent to destroy all the corn, which was plentiful.

The results of this Expedition were mixed at best. They did indeed drive the Indians up to Canada and around Fort Niagara. That change was perminent. They did destroy a large portion of their food supply. They did force longer, more difficult expeditions by the Tory's and Indians. However, they did not break the will of their enemy to fight. In fact, 1780 would again see a significant number of war parties enter Tryon County including a major assult led by Col. John Johnson which swept through Harpersfield, down the Schoharie Valley, and back up the Mohawk with devistating results.