Manassas is the first book in a series of historical novels spanning the Civil War. The Brannon family of Culpeper County, Virginia--Abigail, a widow, and her four sons (Will, Mac, Titus, and Henry) and daughter (Cordelia)--work a good-sized, self-sufficient farm. The Brannons do not own slaves, but they are staunch supporters of the South in the conflict that is about to turn into war.

As speculation grows that the North and South will soon be at war, the Brannons have their own problems, not the least of which is the Fogarty clan, a large family of troublemakers. Will Brannon is the county sheriff and kills one of the Fogartys while trying to arrest him for murder. Justifiable homicide or not, the Fogartys vow to avenge the loss of one of their own. Arson, ambushes, and other threats against the Brannon family and farm force Will to leave home.

While tensions mount in Culpeper County, news of Fort Sumter arrives. Will enlists in the Confederate army and marches to the railroad junction at Manassas, suspicious that the Yankees might not be his only enemy on the battlefield. Two Fogartys have also joined his regiment, and they know that deaths in battle are rarely investigated.