Fortunately this extraordinary history of emergency management in the U.S. is now available at no cost. See this chapter: Catastrophe Is Not the End but the Beginning: Two Centuries of Evolution in US Disaster Law and Policy. from The Cambridge Handbook of Disaster Law and Policy. S. Kuo, J. Marshall and R. Rowberry, eds.

https://commons.library.stonybrook.edu/somas_articles/13/

Thanks to Donovan Finn for the citation.