Guelzo joined the History department of
Eastern University (
St. Davids, Pennsylvania) in 1991. He was the Grace F. Kea Professor of American History at Eastern, where he was also Moderator of the Faculty Senate (1996–98). From 1998 to 2004, he served as Dean of the Templeton Honors College at Eastern. He joined the History department at Gettysburg College in 2004.
Academic focus Guelzo's principal specialty is American intellectual history, from 1750 to 1865. His doctoral dissertation, "The Unanswered Question:
Jonathan Edwards's 'Freedom of the Will' in Early American Religious Philosophy", was published in 1989 as
Edwards On the Will: A Century of American Philosophical Debate, 1750–1850, by Wesleyan University Press, and won an American Library Association Choice Award. In 1995, he contributed a volume in the St. Martin's Press American History textbook series,
The Crisis of the American Republic: A New History of the Civil War and Reconstruction. One of Guelzo's early works,
For the Union of Evangelical Christendom: The Irony of the Reformed Episcopalians, 1873–1930, won the Albert C. Outler Prize in Ecumenical Church History from the American Society of Church History in 1993. He began work in 1996 on an 'intellectual biography' of
Lincoln,
Abraham Lincoln: Redeemer President (1999), which won the
Lincoln Prize for 2000 and the 2000 Book Prize of the Abraham Lincoln Institute. He followed this with ''Lincoln's Emancipation Proclamation: The End of Slavery in America'' (2004), which became the first two-time winner of the Lincoln Prize (for 2005) and the Book Prize of the Lincoln Institute. His interest in the
American Civil War was partially motivated by his grandmother, who had attended lectures by the
Grand Army of the Republic as a child. He cites ex-slaves who testified that Lincoln, specifically his
Emancipation Proclamation, was responsible for freeing them. In addition to those books, he has produced editions of
Manning Ferguson Force's
From Fort Henry to Corinth (1989) and
Josiah Gilbert Holland's
Life of Abraham Lincoln (1998). He also co-edited a volume of essays on Jonathan Edwards,
Edwards in Our Time: Jonathan Edwards and the Shaping of American Religion (with Sang Hyun Lee, 1999) and an anthology of primary sources on
New England theology from 1750 to 1850,
The New England Theology: From Jonathan Edwards to Edwards Amasa Park (with Douglas R. Sweeney, 2006). His books include
Lincoln and Douglas: The Debates That Defined America (2008);
Abraham Lincoln as a Man of Ideas (2009), a collection of his previously published essays; and
Lincoln (2009), a volume in Oxford University Press's "Very Short Introduction" series.
Criticism and commentary Matthew Pinsker notes that Guelzo, with his religious training, often emphasizes religious themes that other historians have neglected. Guelzo argues that Lincoln championed the cause of individual rights partly because of his profound fatalism and what Guelzo identifies as "a lifelong dalliance with Old School Calvinism." Guelzo created a controversy among younger historians of the Civil War when Earl J. Hess reported that Guelzo believed that scholarly blogging was "entirely negative. I consider blogging to be a pernicious waste of scholarly time." Rachel Shelden has noted that Guelzo's
Fateful Lightning: A New History of the Civil War and Reconstruction (2012) is heavily focused on Lincoln. She asserts that little in the book is new, and much is based on old-fashioned historiography. She says he underplays the recent scholarship on the home front, environmental concerns, and medical issues and gives only cursory attention to the black experience or to the complexities of Reconstruction. In 2019, Guelzo denounced
The 1619 Project as "polemic," "conspiracy theory," "ignorance," and "evangelism for a gospel of disenchantment whose ultimate purpose is the hollowing out of the meaning of freedom." In 2020, Guelzo participated in the White House Conference on American History, for which he was criticized by other historians. He responded by writing, "I will take the opportunity of any platform offered me short of outright tyrants, depraved fools and genocidal murderers to talk about American history." Guelzo did not serve on the subsequent
1776 Commission, whose membership did not include any historians.
Affiliations Guelzo has been an American Council of Learned Societies Fellow (1991–1992), a visiting research fellow at the McNeil Center for Early American Studies at the University of Pennsylvania (1992–1993), a Fellow of the Charles Warren Center for the Study of American History at
Harvard University (1994–1995), and a visiting fellow, Department of Politics,
Princeton University (2002–2003 and 2010–2011). He was appointed by President
George W. Bush to the National Council on the Humanities in 2006. ==Awards and honors==