The Burning South by Brenden Bryan

The Burning South is an alternate-history political thriller set in the aftermath of the American Civil War, imagining a world where Abraham Lincoln survives the assassination attempt against him while the country descends into a new kind of conflict.

The story begins with coordinated bombings, sabotage, and insurgent attacks spreading across the South. Former Confederate sympathizers, civilians, and disillusioned Union supporters form a hidden resistance movement led by John Wilkes Booth, who survives and evolves from assassin into revolutionary strategist. Instead of trying to restore the Confederacy directly, Booth seeks to undermine Americans' trust in their own government.

As violence escalates, Lincoln and his administration — including Ulysses S. Grant and Edwin Stanton — create the "United States Protection Corps," a powerful federal security force designed to stop the insurgency. But the Corps quickly becomes controversial as it gains surveillance powers, conducts raids, imposes curfews, and creates secret watchlists.