The Ace’s Bounty by Jason B. Baker
After fighting guerillas and bushwhackers in Missouri during the Civil War, brothers Elijah and Moses Barber return home to a life of poverty.
A dark cloud hangs over their service. Their parents are dead; their farm is a failure, and townspeople and the kin of those they served with give them a mixed reception. They have no prospects and no skills other than knowing they developed a knack for riding, shooting, and tracking down outlaws.
A chance encounter with a new U.S. Marshal offers them work as deputies. Moses realizes it’s the best way for their skills to earn a living, but Elijah wants to leave that sort of thing in the past. When they hear the man they’ll be chasing is one who haunts their past, the opportunity brings a chance for justice…and revenge.
Now the brothers must sort out their own relationship, make peace with their childhood mentor, and figure out the U.S. Marshal who might not be who he says he is. Only then can the brothers find peace and prosperity in their post-Civil War world.