By Keisha Hatchett
Updated April 29, 2015 at 04:38 PM EDT
Credit: Jeff Kravitz/FilmMagic

With British heavyweight Downton Abbeyheading into its final season in 2016, PBS hopes to fill that void with its first American drama in more than a decade. The network announced Wednesday that Mary Elizabeth Winstead, former How I Met Your Mother star Josh Radnor and Gary Cole will star in Mercy Street, a Civil War drama based on real events at Mansion House Hospital in Virginia.

The story follows spirited abolitionist Mary Phinney (Winstead) and Confederate darling Emma Green (newcomer Hannah James), volunteer nurses with opposing views forced to work together in Green’s family hotel—which was converted into a Union Army hospital called Mansion Hospital. Radnor will play Jedediah Foster, a contract surgeon and son of an affluent Maryland slave-owner. Cole, meanwhile, is set to portray patriarch James Green Sr., a man struggling to keep his business afloat.

Additional stars joining the cast include Peter Gerety (Syriana, Charlie Wilson’s War, The Wire), Norbert Leo Butz (Bloodline), McKinley Belcher III (Power, Madam Secretary, Chicago PD), Shalita Grant (NCIS: New Orleans, Bones), Jack Falahee (How to Get Away With Murder), AnnaSophia Robb (The Carrie Diaries, The Way, Way Back, Bridge to Terabithia), Cameron Monaghan (Shameless), Donna Murphy (Resurrection, Hindsight), Tara Summers (Stalker, Rake, Boston Legal), L. Scott Caldwell (Southland, Lost, ER, The Fugitive), Suzanne Bertish (Rome), Wade Williams (“Prison Break, Draft Day), Luke Macfarlane (Brothers and Sisters), Brad Koed and guest star Cherry Jones (24).

Joining Downton Abbey as part of theWinter 2016 lineup, the six-part series is executive produced by Ridley Scott, David W. Zucker of Scott Free, Lisa Q., and David Zabel. In other news, PBS has yet to set an American airdate for the Sherlock Christmas special which heads to U.K. televisions later this year.