They were the westernmost tribe of the Five Nations of the Confederacy which dominated the area south of the Great Lakes in present-day New York and Pennsylvania.

These tribes are among Iroquoian languages-speaking peoples who long inhabited areas along the upper St. Lawrence River and Great Lakes.

As the Seneca had been allies of the defeated British, their lands were among territory ceded to the United States, without consultation with the Iroquois.

The Genesee Valley Canal was completed around 1853 to connect markets from the south of the state to the Great Lakes.

The Rail and Titsworth Canal Warehouse in Belfast was listed on the National Register of Historic Places in 2000 as an important structure from this time period.

[3] In the mid-19th century, new ethnic English migrants, many from eastern Yankee New York and New England, were resisted by many of the Irish residents.

Although most of these clashes were minor, a larger conflict occurred from 1846–1847, when a food shortage in the area raised tensions.

New waves of Irish immigrants were entering New York in this period as refugees from the Great Famine in Ireland.

Facing Jake Kilrain in Richburg, Mississippi that August, Sullivan lasted for 72 rounds before being declared the winner.

In 2009, the Belfast training barns, which had been virtually untouched for more than 120 years, were adapted for use as the world's only Bare Knuckle Boxing Hall of Fame.

Since the 1970s, several pirate radio stations have used the Belfast post office as a mail drop to receive letters from listeners.

The Genesee River flows northward through the northeast corner of the town and is partly paralleled by New York State Route 19, which intersects County Road 26 in Belfast hamlet.