The area comprising Chemung County was located along the Forbidden Trail connecting all the major Native American villages from the Susquehanna River through the Chemung Valley and westward to Ohio. Guarded by the Senecas, the trail was forbidden to whites and enemy tribes. The first European to successfully navigate this path was a Moravian missionary who traveled through the area in 1767.
By the fifteenth century, the Chemung Valley was settled by the Andaste or Susquehannocks, an Iroquoian tribe not a member of the Confederacy. With their flight from the region in the mid-sixteenth century, the valley came under the protection and control of the Senecas and was home to temporary settlements of refugee tribes from the south and east.
At the Battle of Newtown on August 29, 1779 the Native Americans, fighting with their Tory allies, were driven out of the Chemung Valley by the Continental Army led by Major General John Sullivan. This action opened the area to white settlement.
The name "Chemung" is derived from the Algonquians who found a mammoth tusk along the river. It means "place of the horn." Horseheads was so named after Sullivan's troops disposed of worn out pack horses and left their skulls to bleach in the sun.
The Southern Tier was part of the large county of Tioga that was organized by the 1791 Legislature. Chemung County was established by an act of March 29, 1836. Primitive toll road connections led to the need for a canal. The Chemung Canal was opened in 1833, connecting Elmira with Seneca Lake and the Erie Canal. Another landmark came on October 2, 1849, when the New York and Erie Railroad was completed from Binghamton to Elmira. North-south railroads came shortly after and Elmira found itself the hub of a railroad network. Under the leadership of John Arnot Sr., the Junction Canal opened in 1856 and Elmira became the principal coal distributing point in New York State.
Mark Twain (Samuel Langhorn Clemens) is buried in Elmira's Woodlawn Cemetery. He married Olivia Langdon of Elmira in 1870 and for twenty years spent his summers here at Quarry Farm. While in Elmira, Twain worked on several of his masterpieces (including The Adventures of Tom Sawyer and Adventures of Huckleberry Finn) in his octagonal study overlooking the hills surrounding the Chemung Valley. The study has been moved to the Elmira College Campus.
The Chemung Valley suffered $291 million in damage during the Tropical Storm Agnes flood of June 23, 1972. The by-product of this flood was the sponsoring and completion of the Newtown-Hoffman Creek Watershed by the Chemung County Legislature. This large watershed project, along with the Federal Tioga-Hammond Dams, provide flood protection and water recreation of all kinds. The City of Elmira and County of Chemung have recovered. To meet the needs for development of our industries and cultural institutions, a complete revamping and updating of our water system has been accomplished.
Today, Chemung County's industries are wide ranging. Some major corporations are Schweizer Aircraft, Kennedy Valve (fire hydrants), Toshiba Display Devices, Hardinge Tools, ADtranz (mass transportation vehicles), Hilliard Corporation, Anchor Glass Container, Corning Consumer Products, Artistic Direct, Howell Packaging and Purolator Products.
Several local citizens have risen to prominence including Tommy Hilfiger, Brian Williams of NBC news, NASCAR driver Geoff Bodine, the late football star Ernie Davis) and Eileen Collins, the first woman to command a space shuttle mission.