Brother is pitted against brother in this Civil War novel, but not in the usual one-fights-for-the-North, one-for-the-South way. Birthright revolves instead around a feud that began when a Vicksburg planter died and left most of the family fortune to the oldest son. The excluded sibling, a rake, sues and hires a killer, whose plot against the older brother fails. Just as war is breaking out, the miscreants flee; they will, of course, be back, and it is a strength of the book's plot that the developments are credible but not predictable. Meanwhile, civil war is breaking out, and Vicksburg becomes an early target of Union forces who seek to control the Mississippi River. The town's high position on a bluff over the river makes it easier to defend, and Union General U.S. Grant eventually lays a siege. Rich details about the war and especially the siege help keep the story moving along, which it does to a satisfying finish.