I started reading David M. Potter’s book but quickly found his way of discounting the abolitionists (see https://s-usih.org/2017/08/reflections-on-david-potters-the-impending-crisis-part-5/) as something I wasn’t willing to go on with. Are there any more recent high-quality books covering this period?
I went with “The Battle Cry of Freedom”. So far, it’s an improvement.