Rebel by Bernard Cornwell

Nathaniel Starbuck is a rebel, a young Yankee fighting for the South against the North in the American Civil War.It is the summer of 1861 when Nate arrives in Richmond, Virginia, suddenly to be rescued from a lynch mob by Washington Faulconer who is raising his own Legion in the interests of the Confederacy. Personal and political loyalties are tested to the limit, and Nate quickly learns to fight in his own interests and those of his adopted country and friends while the United States of America tears itself violently, unforgivingly apart in the first bloody battles of the Civil War.