And Union soldiers who considered the thousands of slaves crossing the river to freedom more a nuisance than anything else.

"Over the last six months, the GWF has thoroughly researched the history of Kenmore during the Civil War, and in the months leading up to the battle of Fredericksburg in particular," according to Budinger. "The characters in the play come directly from that research."

It revealed the names and ages of the seven slaves who worked on the property, as well as those of the Harrison-Gordon family members who owned Kenmore then.

"We took no liberties" with historical facts, said Alma Withers, director of educational programs for The George Washington Foundation.

On Saturday morning, an audience of about 50 traversed the grounds, "eavesdropping on the conversations," as Budinger put it.

During a Kenmore scene titled "Going, Going Gone," a slave in his late teens named Carey, played by Anthony Williams, and Sarah, an older slave played by Dana Foddrell, discussed his plan to escape. Carey has been found on 1862 tax records and in H.C. Harrison's will, and the foundation considers him to have been a likely candidate to cross the river as a "young, unattached male."

Sarah is a fictional character based on the writings of John Washington, a slave who escaped from Fredericksburg.

When Carey tells Sarah he plans to cross the river to the Union side, she exclaims, "You a slave! You a slave! Dear God!"

"I'm gonna join up with the North," Carey says.

"With the Yankees?!" she says.

He says he doesn't believe what he's hearing from whites--that the Union plans to ship the slaves off to Cuba.

Sarah tells Carey he has no choice. He is a slave. He must do his master's bidding.

"You can choose, and I choose to be a free man," Carey responds.

Act Two took place Saturday at Ferry Farm on the Stafford side of the Rappahannock. There the audience watched a final scene, set in a Union encampment.

The characters included two Union soldiers, both, Budinger said, based on "real soldiers who were stationed at Ferry Farm in 1862, and wrote letters home, describing the tide of runaway slaves entering camp every day."