Based on real events, MERCY STREET is a PBS original miniseries about an inexperienced New England nurse and ardent abolitionist working in the South during the Civil War. Mary Phinney (Mary Elizabeth Winstead), aka Baroness Von Olnhausen, left Boston after being widowed to nurse Union officers back to health. Sent to serve as the head nurse at Mansion House, an Alexandria luxury hotel that now serves as the area's Union Army Hospital, she must quickly adapt to the horrendous conditions while negotiating her place among Army doctors such as surgeon Byron Hale (Norbert Leo Butz), the more modern, civilian doctor Jedediah Foster (Josh Radnor), and the arrogant Nurse Anne Hastings (Tara Summers), who worked with Florence Nightingale in Crimea. Luckily, the kind chaplain, Henry Hopkins (Luke McFarlane), and laborer Samuel Diggs (McKinley Belcher III), a free man with a secret medical background, offer her support. As she works hard to keep going, she crosses paths with Emma Green (Hannah James), the naive adult daughter of the Southern loyalist hotel owner, who is struggling to find her place in the Union stronghold, which marks the beginning of an inevitably changing South.