This battle, which was the most significant military engagement of the campaign, took place at the foot of a hill along the Chemung River just outside what is now Elmira, New York.

The hillside, running southeast to northwest next to the Chemung River, was a mile long at its crest, which rose 600 feet (180 m) above the path at its base leading into the Delaware village of Newtown.

A small watercourse, called Baldwin Creek, ran through the hollow and emptied into the Chemung River (referred to as the Cayuga branch in Sullivan's reports).

[2] Butler and Brant suggested that, because of the size and composition of Sullivan's forces, harassment raids would be more effective than making a stand.

[1] The Rangers and their native allies hastily constructed a horseshoe-shaped camouflaged breastwork of logs about 150 feet (46 m) up the southeast spur of the hill, within musket range of the path.

On the morning of Sunday, August 29, about ten miles upriver from Fort Sullivan, the advance guard, three companies of riflemen formerly with the Provisional Rifle Corps of Colonel Daniel Morgan, drew close to Butler's position.

Crossing the swampy marsh (which Sullivan termed a "morass") in Hoffman Hollow slowed the advance of Poor's and Clinton's brigades, disrupting the timing of the plan, and this provided just enough delay to allow Butler and the Iroquois to escape along the crest of the hill.

The artillery barrage opened well before Poor and Clinton were in position which forced the Rangers and Iroquois back from the breastwork before they could be encircled.

[4] Assigned to the extreme left of Poor's assault formation, the regiment climbed where the slope was steepest and lagged considerably behind the rest of the brigade.

To commemorate the battle's 100th anniversary in 1879, a small parcel of land atop what is now known as Sullivan Hill was donated to create Newtown Battlefield Park.

That same year, 15 acres (6.1 hectares) of land including the park was deeded to the State of New York and named the Newtown Battlefield Reservation.

6866, which directed Secretary of the Interior Dirk Kempthorne to conduct a special resource study to evaluate the significance of the Newtown Battlefield and the suitability and feasibility of its inclusion in the National Parks System, was put forth for consideration by Congressman Randy Kuhl.