Renowned actors Edward Asner and Blair Underwood (L.A.Law, Full Frontal), along with a superb supporting cast, portray scenes from the lives of Garrett, Still, and the people to whom they dedicated their lives. Scenes filmed on location in the historical settings where these freedom fighters undertook their noble and dangerous work lend an authentic air to the production.

Virtually unexplored in films about this era, William Still's landmark book, The Underground Railroad, is the most substantial surviving first person account of the secret activities of this anti-slavery movement. Still courageously archived his correspondence with Thomas Garrett in spite of severe penalties that were reserved for proven fugitive-helpers. He further documented hundreds of eyewitness accounts of harrowing escapes from the bonds of slavery. The result of this brave work, Still's book, provides the narrative backdrop for Whispers of Angels.

Whispers of Angels takes its viewers along the very roads traveled by the weary fugitives fleeing the south, through the historic Delaware communities of Camden, Dover, Odessa, New Castle and Wilmington. "Conductors" secretly led escaping slaves north over the St. Jones, Christina and Brandywine rivers and across the Mason Dixon Line into Pennsylvania where many traveled onward as far as Canada, where (prior to the passage of the Second Fugitive Slave Law) British law forbade slave catchers and frustrated former owners from chasing and recovering what they considered lost "property".