"The Rock of Chickamauga," presenting a critical phase of the great struggle in the west, is the sixth volume in the series, dealing with the Civil War, of which its predecessors have been "The Guns of Bull Run," "The Guns of Shiloh," "The Scouts of Stonewall," "The Sword of Antietam" and "The Star of Gettysburg." Dick Mason who fights on the Northern side, is the hero of this romance, and his friends reappear also.