Raid on the Atlanta. Nathan Tower Novels of Espionage and Intrigue

The war ended in 1865. The fighting never stopped. When Julia Parrish escapes justice for murder, Commander Nathan Tower of the Office of Naval Intelligence sees an opportunity. Her family's network of Confederate sympathizers is still active-and Tower intends to destroy it from within. His weapon is Lucinda Meadows, an untested operative posing as a wealthy Virginia widow. Her mission: infiltrate a violent organization called the Second Generation and uncover their plans before they can strike.
Her target is Charlie Parrish, the overlooked brother desperate to prove himself. Her obstacle is Samuel Lennox, the suspicious leader who doesn't believe a word she says. Her unexpected ally is the legendary General Jubal Early-vain, temperamental, and completely charmed. As Lucinda is drawn deeper into the conspiracy, she takes increasingly dangerous risks. An unauthorized trip to Richmond. A lie that could get her killed.
A secret she keeps from the one man who might save her. The target is the USS Atlanta, one of the Navy's new steel warships. The trap is set for a midnight raid on the Delaware River. But in the world of espionage, traps have a way of springing in unexpected directions. And the Parrish family has not forgotten her. A tale of deception, divided loyalties, and shadow warfare in the aftermath of the Civil War.