Long-buried Chester County Revolutionary War cannon has a new home at Warwick Furnace

WARWICK — One of four Revolutionary War-era cannon unearthed on the grounds of the former Warwick Furnace has a new home to help display and protect its historic legacy.

From 1742 to 1765, the Warwick Furnace was busy making flat iron plates for Franklin stoves.

Production had begun after ironmaster John Potts — the founder of Pottstown — took over the running of the furnace, which had been established five years earlier by his mother-in-law, Ann Rutter Savage Nutt. Pig iron and plate iron manufacture continued through 1765 and then his as-yet unborn country came calling.

As war with Britain crept toward inevitability, the few cannon the colonial forces had in their possession were either taken from the British or from merchant ships which used them for defense against pirates. So with supply low, local production at Warwick Furnace switched to a new, dangerous and illegal product — cannon.

“Britain had banned manufacture of artillery in America, declaring it both illegal and disloyal to cast guns,” according to an article on history.net, so few Americans had much experience with their manufacture, as evidenced by the fact that many failed their initial tests — some exploded. In May of 1776, none of the 200 cannon cast at two Pennsylvania foundries proved usable.

But soon enough, they got better and four months later, nearby Hopewell Furnace had 28 cannons of 41 cast proven usable.

One year later, the British captured Philadelphia and after failing at Germantown to counter-attack and re-take it, Gen. George Washington marched his troops to Valley Forge for his famous encampment there. On Sept. 17 of that same year, he and Alexander Hamilton marched 8,000 of his troops to Warwick Furnace area to repair rifles, obtain ammunition and cannons from the many furnaces and forges in the area.

Just as the Americans took cannon from the British, so too did the British capture American cannons. It was to avoid this possibility that at least four cannon at Warwick Furnace were buried alongside the south branch of French Creek. And that’s where they stayed for more than 200 years.

Long rumored to be somewhere on the property, Ray Bentley and Jim Moore decided that once the remains of the Warwick Furnace had became part of the French and Pickering Creek Conservation Trust’s 100-acre Thomas P. Bentley Nature Preserve, the time to find the cannons was at hand. That was April of 2022.

According to Bill Gladden, the executive director of the trust, Martin Helmke, a professor at West Chester University, used a drone with a magnetometer attached, and flew a grid pattern over the area rumored to be hiding the cannon, and it revealed strong iron indications near the creek. On the small excavation crew’s first try, April 14, 2022, they found their first cannon.

“Holy mackerel, it’s a cannon!” Moore recalled saying after he climbed down, trowel in hand, into the 3-foot hole made by the excavator run by Warwick Township Supervisor Jason Swinehart. “At first I thought it was a rock, then maybe a pipe and then I realized it was a cannon,” he said.

They found another on April 18 and two more by May 5.

The cannons were each more than 7 feet long, more than 4,500 pounds, and made to fire 18-pound cannonballs. To the surprise of the excavation crew, two of the cannons were found with cannonballs still in their barrels.

And now one of those cannons has returned to the place it was made, and is housed in a permanent shelter in the 100-acre Thomas P. Bentley Nature Preserve off Warwick Furnace Road.

The design process for a permanent display commenced in July 2022. Construction began earlier this year in July of 2023 and concluded in October.

Swinging his arm wide to indicate the entire furnace site, Ray Bentley told the small crowd gathered for the shelter’s ribbon cutting that “this was all invisible from the road. The place was a jungle, like Indiana Jones finding just the furnace. The previous owner did not care about history at all.”

“There was a tree growing on top of the furnace and Jason almost single handedly got it out in a display of an incredible amount of stubbornness,” Bentley said. “It’s out in the woods now and its named ‘Jason’s Stump.’”

That pluck and stubbornness was equally evident in the people who began making cannons from scratch, Bentley said. “It was prohibited, the audacity of the it all is amazing. This is for the people who stuck with it, who stayed with it.”

“In the late 1700s, the population of all of Chester County was 28,000,” said Gladden. “In 1990, it was 376,000 people and now its well over half a million.”

As that population grows, it makes the preservation of open land in the county, and the history that is linked to it, all the more urgent, he said.

“We dug up these cannons that were made and buried over 200 years ago and we stand here today looking out over a landscape that is very similar to what it was then,” said Gladden. “Our charge as an organization is thinking into the future and what the preserve will look like 250 years from now. Because of our collective efforts, not only to conserve the land, but to help connect people to these stories within the land, our hope and goal is that 250 years from now people will stand here and appreciate the same vistas we have the privilege of experiencing today.”

The funding for the shelter came from Ray and Terry Bentley, the Marshall-Reynolds Foundation, and the Marjorie L. and Arthur Miller Foundation.