In the autumn of 2013, I arrived in Ithaca, New York, to begin a postdoctoral fellowship in security studies at Cornell University. One of the major reasons I chose to attend Cornell was that it was the home of Walter LaFeber, one of the true giants of twentieth-century diplomatic history. LaFeber had been at Cornell since 1959 — the same year he received his PhD from the University of Wisconsin — and had trained generations of diplomatic historians who transformed the study of US foreign relations in the twentieth century’s second half. Despite the fact that LaFeber was retired, I wanted to at least meet him, which I’m happy to say I did.

LaFeber was one of the most influential members of the so-called “Wisconsin School” of diplomatic history, which coalesced at the University of Wisconsin around the person of William Appleman Williams, whose classic 1959 The Tragedy of American Diplomacy launched the “revisionist” approach to US foreign relations. Though the contributions of revisionists like LaFeber and Williams cannot truly be reduced to a sound bite, in essence their major intervention was to highlight the centrality of economic considerations to US foreign policy. This insight shaped, and continues to shape, the field of diplomatic history.

Throughout his career, LaFeber wrote books about an astonishing diversity of topics: the War of 1898, the Vietnam War, the Cold War, US-Japan relations, the 1968 election, and Michael Jordan, to name only a few. My personal favorite book of LaFeber’s is his first, 1963’s The New Empire: An Interpretation of American Expansion, 1860–1898, which explores the economic sources of US expansion. It is, without exaggeration, a must-read for any socialist who desires to understand the history of US empire.

LaFeber also provided a powerful model of the engaged historian. As his students Andrew J. Rotter and Frank Costigliola noted in a 2003 tribute to him, LaFaber’s scholarship was always “impelled by concerns with current events.” LaFeber wanted his writing to impact how Americans understood the dark elements of their nation’s history so that they could make better decisions in the present, an important contribution in a world in which, as Rotter and Costigliola put it, “American foreign policy [is] too often celebrated by other scholars and the American public.”

Walter LaFeber left behind a legacy that scholars of US foreign policy will be learning from, and wrestling with, for as long as history remains a viable profession. He was a giant in the field, to whom much of the critical history written about US foreign affairs in the previous fifty years is indebted. Few scholars can say, as Walter LaFeber could, that they helped transform a field and its relationship to power. For that, and much more, he will be missed.