 By fall, surgeon Fleming was assigned to Lewis' headquarters at Fort Dickenson on the Cowpasture River near present Millboro, but his request to transfer to the regular army was ignored.In 1758, he accompanied Major Lewis and Virginia troops northward in what became known as the Forbes expedition, after General John Forbes, who assembled many colonial troops at Raystown, Pennsylvania north of Fort Cumberland and attacked the French at Fort Duquesne.Fleming continued to participate in the Anglo-Cherokee War in 1759–1761.