For reconstruction I would recommend A Short History of Reconstruction which is an abridgment of Reconstruction: America's unfinished revolution by Eric Foner. State of Rebellion by Richard Zuczek, The Bloody Shirt by Budiansky, and Race and Reunion by David Blight are all very good books about Reconstruction

I've been reading a lot about the history of racism in politics in the US, and in my research, historians tend to point to two major exceptionally radical periods in American history: Reconstruction and the Civil Rights Movement. What was the recipie for these exceptional periods, and how can they be recreated. Though an answer would be welcome, I am really looking for book recommendations.