Swords of Steel — Eli Singmaster

In 1859 a 12-year-old John Deane lives in Gettysburg, Pennsylvania with his family. He is friends with Nicholas, a black servant, with whom he is training a colt. He is devastated when Nicholas is kidnapped by slave catchers and sent to the South to be sold. He learns that his father is a conductor on the Underground Railroad, and he visits Harper's Ferry where he witnesses John Brown's raid. When the war reaches Pennsylvania, his house is seized by the Confederates, and he is locked in the cellar. However, he is helped by the troop's cook, his old friend Nicholas. Later he joins the Union Army and sees the final events of the war.