Revolutionary War USA Continental Army Vest Button Dug at Battle of Newtown

Vest size button dug at Gen. Sullivan's Continental Army Camp.  Full shank, missing chipped rim as seen in photo. Very rare site.  Strong USA, good pie crust rim remaining.  
 
The Battle of Newtown (August 29, 1779) was a major battle of the Sullivan Expedition, an armed offensive led by General John Sullivan that was ordered by the Continental Congress to end the threat of the Iroquois who had sided with the British in the American Revolutionary War. John Butler and Joseph Brant did not want to make a stand at Newtown, but proposed instead to harass the enemy on the march, but they were overruled by Sayenqueraghta and other Indian chiefs. The Battle of Chemung (August 13, 1779) was the only other major battle of the Sullivan Expedition where the Continental force lost six dead and nine wounded.
This battle, which was the most significant military engagement of the Sullivan Campaign of 1779 and played a crucial role in America's Revolutionary War,[2] took place at the foot of a hill along the Chemung River just outside what is now Elmira, New York.