The slaves that ventured into the Great Dismal Swamp to find freedom must have thought they’d discovered the perfect place to escape their oppressors.

Journeying into the site of a former maroon community earlier this week, researchers from American University and several other institutions trudged and waded through bog and swamp water for 20 minutes, piercing the thick vegetation.

They reached what the machete-wielding Daniel Sayers, trained in philosophy, anthropology, history and archaeology, director of the Great Dismal Swamp Landscape Study, described as a 20-acre island, eight or nine feet “above swamp level.”

Coming to a stop and unburdening themselves of provisions, metal detectors, ground-penetrating radars and other instruments, they peeled back tarpaulins to reveal a dig site Sayers believes may show that toward the end of their time in the swamp, the maroons had grown insecure in their surroundings, lit by cypress-filtered sunlight.

“What we are finding in this area … is a concentration of what I would call munitions-stuff,” Sayers said, standing beside an excavated square measuring 18 feet by 18 feet, where he believes a “defensive structure” may have once rested.

Sayers has concluded from his decade of field research that maroon communities thrived in the swamp between the early 1600s and the end of the Civil War.

Early on, marooners were indigenous Americans displaced by the colony that spread out from Jamestown. Later, more and more were escaped slaves, which became the majority.

In a world such as theirs, where perhaps only five percent of materials utilized came from outside, maroons may have looked to as weaponry the seemingly innocuous items that the researchers have screened from the soil — nails, pebbles, shards of glass.

“Even stuff like pebbles can be used in the absence of lead shot,” Sayers said. “Even the nails.

“Usually, a historic site that has a structure, when you find nails, you find them by the truckload. Here, we’ve found maybe eight nails total.”

For his dissertation several years ago, Sayers focused on a nearby site with half the elevation of where the possible defensive structure was located.

The dissertation site is older, Sayers said, adding, “Moving upward happened for defensive reasons — maybe symbolic.”

So if the maroons had felt the need to defend themselves, why? Encroachment of the outside world, Sayers believes.

Isolation was a treasured ally of the maroons. Today’s swamp covers only 10 percent of what it did, Sayers said, and roads were non-existent. Mainstream civilization was far away.

But the draining and logging of the swamp brought labor camps. “It was around 1800 when the lumber companies really got a hold in the swamp,” Sayers said.

Pushing ever deeper inside to harvest the valuable timber, labor camps started encountering the hundreds of scattered interior maroon camps, he said.

Sayers and other researchers, including Daniel Lynch of the University of Massachusetts   Amherst, believe maroons subcontracted themselves to workers from the labor camps, who were paid for shingles on a quota system.

Maroons in turn would have been paid with items from the outside, and pits to store them have been discovered at older maroon settlement sites, they say.

But “I don’t think they wanted the outside stuff because they were resisting it for all those centuries before,” Sayers said.

“Once you start introducing outside stuff, it changes the way people live.”

The maroons could also have felt threatened by other groups that for different reasons had sought refuge in the swamp, Sayers said, such as fugitives from the law.

“I think it’s a more complex vision of an internal community,” he said.

In Suffolk’s backyard, the Great Dismal Swamp Landscape Study is raising some very poignant and important questions.

According to Kathryn Benjamin, a doctoral student from the University of California Berkeley’s Department of African-American Studies, that maroons not only escaped captivity and established their own free communities in the swamp, but were likely prepared to defend them, shows black resistance started well before the civil rights movement that peaked in the 1960s.

“We are at a serious disadvantage in this country if we don’t know it, and we don’t know it,” she said of the swamp maroons’ story.

“Maroonage is one of the most overt kinds of slave resistance that existed, period.”

Benjamin, who has also been seeking passed-down oral histories on the swamp maroons from Suffolk families, says researchers like her have met resistance from folks who might prefer the stories remain absent from the historical record.

“We have all faced skepticism in our projects and been marginalized in doing this work,” she said.

Sayers said this year’s will be the last five-week field class he brings to the swamp. It’s time to start sifting through and interpreting the trove of accumulated artifacts and data, he said.

“Hundreds and hundreds” of folks have contacted Sayers about his work in the swamp over the years, he said.

“They identify with the swamp in one way or the other.”