EASTHAMPTON — Imagine Easthampton in 1900. West Boylston Manufacturing Company had just moved its fabric-producing business to one, lone-standing mill building. The company would soon build five more factory buildings, creating the community’s first million-dollar corporation.

The company — employing mostly French Canadian and Polish immigrants, male and female, old and young — then built more than 400 living spaces for its workers in the New City area. A footbridge was built over what is now known as the Lower Mill Pond, allowing employees to cross the water to get to and from work. This industrial boom then brought an increase in population: in 1900, Easthampton had 5,003 residents, a figure that surged to 11,261 by 1920.

Those were just some of the historical insights shared by Easthampton High School history teacher Kelley Brown on Monday night during the city’s celebration of the nation’s 250th anniversary.

“Easthampton has done such a great job of repurposing the mills and repurposing this space,” Brown told the crowd from the stage at Millside Park. “I thought that you might want to know a little bit about this space that you’re actually standing on, sitting on and living next to all the time.”

Dozens gathered to hear Brown speak at the finale of the city’s Millside Summer Series, a five-day series spearheaded by Mayor Salem Derby that featured 2026 World Cup soccer watch parties, live concerts and various community activities. The last day brought together a celebration of Easthampton, America’s 250th anniversary of independence and the high school’s We The People Team — which Brown coaches.

The information shared by Brown comes from a culmination of sources, primarily the Easthampton Historical Society, which she has worked with for the past 20 years researching and teaching local history. Additional sources included Forbes Library, the University of Massachusetts Amherst Special Collections and several local residents past and present, such as Edward Dwyer.

The occasion drew a visit from Lt. Gov. Kim Driscoll, who made the celebration one of several stops in western Massachusetts communities on Monday. As the state hold events throughout the remainder of the year to commemorate the history of the Commonwealth and the wider nation, Driscoll said Massachusetts has historically served as an early leader in the country’s founding.

“While we have all these figureheads in our history books that we can point to, oftentimes it was the ordinary individuals living in communities who helped ensure America’s democracy and the founding of our nation,” Driscoll said at the event. “Going back into Easthampton’s history, there were local people who clothed, fed through grains raised, through fabrics made, [President George] Washington’s army,” in the late 1700s.

Derby echoed similar sentiments in an interview, acknowledging that Easthampton’s rich history contributed to the development of Massachusetts. “Easthampton has a rich history with 250. It was great to be able to highlight that (at the event),” he said.

Derby also displayed a slideshow showing that before the 16th century — and long before Easthampton incorporated as an independent town separate from Northampton and Southampton in 1785 — the Norwottuck peoples fished the Manhan River.

“The same ground that was called Pascommuck, that was farmed by Norwottuck families, that sent men to Lexington, that incorporated itself in 1785 — is the same ground we govern today. We are the long way home,” Derby said in a statement.

Derby presented the We The People team with a mayoral citation honoring their achievements, while Driscoll thanked them for representing Massachusetts at civic competitions each year, having won the Center for Civic Education We the People State Competition for nine consecutive years.

Similar to Driscoll’s comments, Brown also discussed how Easthampton’s mill workers often produced different materials throughout the nation from its factories. In 1918, Brown said there were two strikes at the West Boylston Mills during World War I, when materials were being produced for the war.

Brown said during the second strike on July 18 of that year, as reported by the Daily Hampshire Gazette, a crowd of strikers workers — predominantly Polish women and children — gathered at noon on the pond’s footbridge to protest their treatment. The demonstrators attacked mill operators with everything from ammonia to rotten eggs.

“Essentially, all the workers who were walking home at lunch had nowhere to go but into the group of protesters who were going to attack them with ammonia, rotten eggs, mustard, ginger and red pepper,” Brown said.

Thirty-six Polish women were arrested and the National Guard was brought in to put down the strike. But the efforts paid off; a couple of years later the workers received raises and had their hours reduced.

Attending this week’s event, U.S. Navy veteran Joe Broussard said the 250th anniversary of America feels “a little different.” Broussard, who now lives in Sunderland, said he used to work in one of the former factory buildings in Easthampton in 1975, manufacturing clothes.

“Easthampton was a really booming town back then, booming like crazy back in the 60s and 70s,” Broussard said.

While the factories were booming, Broussard said the downtown streets, particularly Cottage Street, were almost empty on any given day. That has certainly changed, he said.

“I remember you’d be driving down the street, there’s hardly any kids or anybody on the street,” Broussard said. “Now you go down there, holy crap. Even my wife says, ‘goodness look at all the people all over the place.'”

To conclude the day and the Millside Summer Series, 4Life Entertainment, the company producing the various shows and events, ended it with a laser show, gleaming light beams into the night sky.