[3] Easthampton was first settled by European immigrants beginning in 1664 as the village of Pascommuck and was originally part of Northampton.

On 24 May 1704 during Queen Anne's War, a party of 72 Native Americans attacked the village, killing 19 of 38 residents.

The town grew primarily around the Manhan River, both through its phase as a strictly agricultural community and later, through the Industrial Revolution, when mills and factories were first built in Easthampton, mainly in connection with textile manufacturing and its offshoots.

The company specialized in cloth-covered buttons—a coveted item at the time—and to facilitate the operation of the machinery, a local brook was dammed, creating Nashawannuck Pond.

Other mills soon opened nearby, a number of them specializing in elastic and rubber thread manufacturing.

Constables were replaced by the town's first police officer in 1871, the same year that Easthampton became a regular stop on the railroad.

The town's public library opened in 1881, and fourteen years later in 1895 the community was introduced to two new innovations, telephones and streetcars.

During World War I, the town's mills all obtained federal wartime contracts and did well financially, but long before the Great Depression hit, many factories owners were already laying off employees, seeking mergers with other companies, or looking for buyers for their facilities.

[6] World War II provided some relief for the Easthampton economy, as several of the older textile companies as well as newer heavy manufacturing corporations received another round of federal contracts.

In November 2018, the administration of Massachusetts Governor Charlie Baker announced a $3.5 million grant through the MassWorks program to the Ferry Street Mill redevelopment project in the city.

It is bordered by Southampton and Westhampton to its west, by Holyoke in Hampden County to its east and south, and by Northampton to its north.

Interstate 91 and U.S. Route 5 cross the northeastern tip of Easthampton near the Connecticut River, leading north to Northampton and south to Holyoke.

In 1902, the town responded to the population increase resulting from the growth of the West Boylston and Hampton Companies.

In 2017, lawyer Nicole LaChapelle defeated long-time district councilor Joy Winnie to become the city's next mayor.

In 2019, the city voted by referendum to adopt single-winner ranked-choice voting to elect the mayor as well as city council members from single-winner districts, while retaining plurality first-past-the-post elections for the four at-large council seats.

[22] Easthampton is located in the Eighth Massachusetts Governor's Council district and is represented by Tara Jacobs (D-North Adams).

The Mount Tom State Reservation extends into the eastern part the city, and many local residents hike up to enjoy the view of the Pioneer Valley from the rock ledges.

Mount Tom, with a summit elevation of 1,202 feet (366 m), is the highest traprock peak on the Metacomet Ridge, a linear mountain range that extends from Long Island Sound to the Vermont border.

The Arcadia Wildlife Sanctuary, part of the Massachusetts Audubon Society, is split between Easthampton and neighboring Northampton.

The High Victorian Gothic town hall was built in 1869 by Boston architect Charles Edward Parker.

Every summer, MillPond.Live brings a festival series designed to unite people from all walks of life to Easthampton's Millside Park, with local and international music, food, art, and community.

Some of the events that ECA organizes include: Art Walk (a free and family-friendly event held throughout the city every second Thursday of the month); Cultural Chaos (a street festival that celebrates the Cottage Street Cultural District); and Porchfest (Easthampton's very first Porchfest was held in September 2023 and will return in 2024).