Onondaga County is part of the Syracuse, NY Metropolitan Statistical Area.
The name Onondaga derives from the name of the Native American tribe who historically lived in this area at the time of European contact, one of the original Five Nations of the Haudenosaunee. They called themselves (autonym) Onoda'gega, sometimes spelled Onontakeka. The word means "People of the Hills." Sometimes the term was Onondagaono ("The People of the Hills"). The federally recognized Onondaga Nation has a reservation of about within the county, on which they have self-government.
When counties were established in New York in 1683, the present Onondaga County was part of Albany County. This was an enormous county, including the northern part of New York State as well as all of the present State of Vermont and, in theory, extending westward to the Pacific Ocean. This county was reduced in size on July 3, 1766 by the creation of Cumberland County, and further on March 16, 1770 by the creation of Gloucester County, both containing territory now in Vermont.
On March 12, 1772, what was left of Albany County was split into three parts, one remaining under the name Albany County. One of the other pieces, Tryon County, contained the western portion (and thus, since no western boundary was specified, theoretically still extended west to the Pacific). The eastern boundary of Tryon County was approximately west of the present city of Schenectady, and the county included the western part of the Adirondack Mountains and the area west of the West Branch of the Delaware River. The area then designated as Tryon County now includes 37 counties of New York State. The county was named for William Tryon, colonial governor of New York.
In the years prior to 1776, most of the Loyalists in Tryon County fled to Canada. The Onondaga were among four Iroquois tribes that allied with the British against the American colonists, as they hoped to end their encroachment. Instead, they were forced to cede most of their land in New York to the United States after the war. Many Onondaga went with Joseph Brant and other nations to Canada, where they received land grants in compensation and formed the Six Nations of the Grand River First Nation.
In 1784, following the peace treaty that ended the American Revolutionary War, the name of Tryon County was changed to Montgomery County. It honored General Richard Montgomery, who had captured several places in Canada and died attempting to capture the city of Quebec, and replaced the name of the hated British governor.
In 1789, Montgomery County was reduced by the splitting off of Ontario County from Montgomery. The actual area split off from Montgomery County was much larger than the present county, also including the present Allegany, Cattaraugus, Chautauqua, Erie, Genesee, Livingston, Monroe, Niagara, Orleans, Steuben, Wyoming, Yates, and part of Schuyler and Wayne Counties.
In 1791, Herkimer County was one of three counties split off from Montgomery (the other two being Otsego, and Tioga County). This was much larger than the present county, however, and was reduced by a number of subsequent splits.
In 1799, Cayuga County was split off from Onondaga.
In 1808, Cortland County was split off from Onondaga.
In 1816, parts of Oneida and Onondaga Counties were taken to form the new Oswego County.
At the time Onondaga County was originally organized, it was divided into eleven towns: Homer, Pompey, Manlius, Lysander, Marcellus, Ulysses, Milton, Scipio, Ovid, Aurelius and Romulus.
Central New York developed rapidly after the New Military Tract provided land in lieu of payment to Revolutionary War veterans. Migration was largely from the east, mostly from New England states. The Genesee Road, which became the Seneca Turnpike in 1800, provided access. Generally settlers preferred higher land, since they associated lowlands with disease. In time, as hillside soil was eroded by early clearing and farming, valley lands were more fertile and highly prized for agriculture as well as for water power, which was the origin of many communities. An early settler of 1823 was James Hutchinson Woodworth, a native of Washington County, NY. He helped clear land for his family's farm in this region before going on to Chicago where he became Mayor.
The city of Syracuse, New York developed relatively late, due to its marshy situation. It was incorporated as a village in 1825 and as a city in 1847; by contrast, the Village of Manlius, along the Cherry Valley and Seneca Turnpikes, was incorporated in 1813. Population of rural towns was greatest in the late nineteenth century, when more people cultivated land and farms were relatively small, supporting large households.
Since that time, agriculture has declined in the county. Some Onondaga County towns like Spafford, New York were largely depopulated, many villages becoming veritable ghost towns. Onondaga County highlands now are more heavily reforested, with public parks and preserves providing recreation. Two Finger Lakes in the county, Skaneateles and Otisco, also attract visitors. The village of Skaneateles on scenic Route 20 has become a major tourist destination.
At the turn of the twenty-first century, population declined in the City of Syracuse while suburban communities generally grew, particularly with tract developments north of the city. Elsewhere, scattered commuter houses appeared, generally on fairly large parcels. The village of Skaneateles and shores of Skaneateles Lake attracted rapid development, demand for property increasing property values remarkably.