The Fire is Upon Us by Nick Buccola. This was an interesting book that came out a really opportune time. It explains a lot of the racism within the Republican voting public and how the GOP has harnessed it.

False Cause by Adam Domby. I liked this b/c it explained some of the political mechanisms used to develop the Lost Cause Narrative and why it was important to local political powers to have that narrative.

Until Justice Done by Kate Masur. I thought it was interesting to see how the South used federal power in the antebellum period to run roughshod over state's rights arguments from the Northern states, exactly the opposite of their later claims after the war.

Postwar by Tony Judt. I don't think there's anything better for understanding the late 20th Century.

The Walter Stahr biographies of Seward, Stanton, and the new one about Chase. These men did so much to shape the modern world and the modern American government system and they really don't get enough credit or focus. Stahr's biographies are fascinating.