The 2020 Journal of the History of Philosophy Book Prize (books published in 2019) is awarded to Sanford Shieh (Wesleyan University) for Necessity Lost: Modality and Logic in Early Analytic Philosophy, vol. 1 (Oxford University Press, 2019). A special Honorable Mention goes to Ada Bronowski, The Stoics on Lekta: All There Is to Say (Oxford University Press, 2019), which came in as a very close second.
Congratulations to Shieh and Bronowski for their hard work!