Horgan’s work is one of the early important works in Southwest history and cultural studies, yet the term regionalist does not do him justice. He uses the American Southwest to examine issues that have universal importance, such as the interaction between humans and environment and how the preconceived ideas that people bring to an environment shape their perceptions of that place. Perhaps a better term for Horgan would be humanist; he is interested in people and their interaction with landscape. Nowhere is this more important than in the arid region of the Southwest.
Great River is a pioneering work in interdisciplinary history. In it, Horgan combines history, geography, anthropology, and sociology. Reviewers have often praised Horgan’s writing skill, and he presents his narrative with the mastery he brings to his novels. Some critics, however, have found Horgan’s bibliography flawed, and others have argued that his historical interpretation is sometimes questionable. As Robert Gish notes, “The book values all human life and its uses of nature, but it champions the stage by stage change which came to the river in terms of [the] ‘progress”’ of the implantation of European and Anglo-American civilization. In Horgan’s defense, he never claimed to have written a definitive, scholarly history of the Rio Grande region but instead a work imbued with imagination. One of his central goals is to bring the region to life.
Horgan’s writings may be divided into two major phases: his writings before World War II and those after the war. Before the war he published a dozen books. The war interrupted his career, and the second stage of his work began with the publication of Great River. He has continued to write both novels and histories as well as producing autobiographical works. He won the Pulitzer Prize for the second time in 1975 for Lamy of Santa Fe, His Life and Times, a biography of John Baptist Lamy, the first archbishop of Santa Fe. Nevertheless, Great River remains central to Horgan’s body of work. In this book the reader finds his characteristic concern with men and women and their place in history and perhaps the best example of his technique of choosing “representative men” to typify a culture and a historical epoch.