In 1835 two Salisbury brothers journey to Washington City from Sandy Creek, New York to promote their town. There they witness the whipping of a slave. Mason Salisbury tries to intervene, and is struck across the face with the whip.
Mason becomes an ardent abolitionist. In 1861 his son, Moreau, is at seminary when Ft. Sumter is fired on. Moreau cannot reconcile "Thou shalt not kill" with killing, even given the abomination of slavery. But his mind is changed when he discovers an escaped slave trying to get to Canada. Moreau and his cousin Merrick join the 24th New York Volunteers, but not before Moreau falls in love with Helen, a local girl.
The summer of 1862 is a succession of battles culminating with is Antietam.
Both Moreau and Merrick are wounded and word of their wounds reaches home. Their fathers go to the battlefield and find their sons in among the other casualties.
Moreau barely survives the trip home, but Merrick dies.
At home, Moreau becomes increasingly depressed. There are arguments with Helen, anger at Mason for supporting the war, and finally a violent father-son confrontation. It is a long, brutal winter. but spring comes, and with it, the renewal of love and trust.