Educated at the University of Rochester, where he worked with Eugene Genovese and Herbert Gutman, Hahn received his Ph.D. from Yale University. His dissertation was overseen by C. Vann Woodward, and later Howard R. Lamar.
He has written on the South, slavery and emancipation, the Populist Era, rural cultures, and social migration. His first book was The Roots of Southern Populism: Yeoman Farmers and the Transformation of the Georgia Upcountry, 1850-1890 (Oxford University Press, 1983). This study was important because it provided a detailed and original account of the political ideology of white southern small farmers. At the time this group, the majority of the American South, had received relatively little scholarly attention. Hahn presented the southern yeomen as non-capitalist in crucial respects, and describes how they were undermined by the increasing commercialization of Southern agriculture after the Civil War.
Several historians have noted that a union of black and white workers is presented as a much more likely possibility in A Nation Under our Feet: Black Political Struggles in the Rural South from Slavery to the Great Migration than it is in Hahn's first volume, The Roots of Southern Populism, in which the Populists were presented as having had almost no interest in a genuinely biracial polity.
Hahn has won a number of teaching awards and has been supported in his research by the Guggenheim Foundation, the American Council of Learned Societies, and the Center for Advanced Study in the Behavioral Sciences at Stanford.
He lives in Bryn Mawr, Pennsylvania.
- 1980 Allan Nevins Prize of the Society of American Historians, for his doctoral dissertation, The Roots of Southern Populism
- 1984 Frederick Jackson Turner Award of the Organization of American Historians, for The Roots of Southern Populism: Yeoman Farmers and the Transformation of the Georgia Upcountry, 1850-1890
- 2004 Pulitzer Prize for History, for A Nation Under our Feet
- 2004 Bancroft Prize, for A Nation Under our Feet
- Merle Curti Award in Social History from the Organization of American Historians.
- Steven Hahn, Jonathan Prude, ed. (1985). The Countryside in the Age of Capitalist Transformation: Essays in the Social History of Rural America. University of North Carolina Press. ISBN 978-0-8078-4139-6.
- Freedom: A Documentary History of Emancipation, 1861-1867. Series III: Land and Labor in 1865. Cambridge University Press. 2004.
- A Nation Under our Feet. Harvard University Press. 2003. ISBN 978-0-674-01169-4.
- Steven Hahn (2006). The roots of southern populism: yeoman farmers and the transformation of the Georgia upcountry, 1850-1890. Oxford University Press. ISBN 978-0-19-530670-5.
- Steven Hahn (2009). The Political Worlds of Slavery and Freedom. Harvard University Press. ISBN 978-0-674-03296-5.
- "Steven Hahn | Department of History | University of Pennsylvania". History.upenn.edu. Retrieved 2013-09-14.
- "Allan Nevins Prize - Past Winners". Society of American Historians. Retrieved 16 March 2011.