A historian of the modern United States, Professor Horowitz's work is meant to help readers think through problems that are often imagined to be without precedent. His research focuses on disasters and the questions they give rise to about race, class, community, trauma, inequality, the welfare state, extractive industry, metropolitan development, and climate change. He is the author of Katrina: A History, 1915–2015 (Harvard University Press, 2020), which won the Bancroft Prize in American History. He has published essays in The Washington Post, Rolling Stone, and The New York Times, and has been featured on NPR and the BBC. As a public historian, he works to support communities as they engage in acts of collective autobiography and serves on numerous boards and commissions as an advocate for the humanities.