SHEFFIELD -- An overlooked piece of African-American history in the Berkshires will soon get national exposure, courtesy of an upcoming PBS special.

Henry Louis Gates Jr., an acclaimed Harvard scholar and director of the W.E.B. Du Bois Institute for African and African American Research at Harvard, traveled to the Ashley House in Sheffield on Tuesday, a TV production team in tow, to film scenes for an episode of the upcoming PBS show, "The African Americans: Many Rivers to Cross."

"We've been here all day, since this morning," said Kate Preissler, the engagement manager for Trustees of Reservations, which protects 110 special or historic places across Massachusetts, including the Ashley House.

Airing sometime this fall, the six-episode series will focus on African American history, from slavery until today. The second episode will focus on Elizabeth Freeman, who successfully sued slave owner Col. John Ashley for her freedom in a Stockbridge courthouse in 1773, blazing a trail toward ending slavery in Massachusetts altogether in 1781.

"Elizabeth Freeman's story is one of the most amazing stories of African-American history, or American history," Preissler said. "It's been hidden in the Berkshires for so long. I'm not surprised, and excited, to see this documentary taken to a national level."

The Ashley House, build in 1735, still stands at 117 Cooper Hill Road in Ashley Falls. Rather than using actors to recreate the era, each of the six episodes in "The African Americans: Many Rivers to Cross" will use historic art, photos, architecture and landscapes to tell the story.

"The house is very good at showing you what it must have been like," said Sabin Streeter, the producer and director of the episode. "Hopefully it will make it clear to the viewers that domestic slaves lived in very tight quarters."

Streeter and Gates have worked on other PBS shows together. At Tuesday's production, Streeter filmed Gates touring the inside and outside of the Ashley House. After Gates was called back to Boston on Tuesday, production had to be sped up.

"The trustees have done a remarkable job with the Ashley House," Gates said via email. "We've visited numerous historical sites for the series, and it's very rare to find a location dating back to the 18th century that is so well preserved."

Streeter and his crew also filmed around Stockbridge, where Freeman's trial was held at a courthouse that has since been demolished.