Dye, Ginny. Bregdan chronicles series #3

Sequel to: On to Richmond

"As her beloved city of Richmond is transformed into a deadly Civil War battlefield, spirited Carrie Cromwell puts her medical skills to work in a Confederate hospital. While she fights to save unknown soldiers, the one she cares about the most is lost to her. Meanwhile in the North, Carrie's dear friends, former slaves Rose and Moses have found freedom at last -- only to be separated by war. Can Moses, now a Union spy, elude those who are searching for him as a runaway slave? Rose decides to join Moses in the North's fight. Inspired by a revolutionary young speaker, she becomes a teacher in the Contraband Camps."--Author's website