Thomas Francis Walsh was born on December 30, 1925, in Boston, Massachusetts. His secondary education was completed at the Boston Latin School. His undergraduate studies at Boston College were interrupted by service in the U. S. Navy during World War II. He took his B. A. from Boston College in 1949, his M. A. in 1951. He held a graduate teaching fellowship at the University of Wisconsin at Madison from 1951 to 1956, where he completed his doctoral studies in 1956. In that same year, he received an appointment in the English Department of Georgetown College to teach eighteenth- and nineteenth-century American literature and renaissance British literature. American literature was his primary scholarly interest throughout his teaching career, all of which was served at Georgetown University. His early publications were primarily on Nathaniel Hawthorne and on American Transcendentalism. He then turned his attention to more recent American authors: Wallace Stevens, Flannery O'Connor, and Katherine Anne Porter.
Professor Walsh's interest in Katherine Anne Porter was inspired by her. In the summer of 1960, he met her several times at the Georgetown home of Marcella Comes Winslow. Several times, he and his friend Louis Dupre, at that time also a professor at Georgetown, escorted Porter to mass at the Priory at Georgetown, and Porter reciprocated by entertaining them at dinner in her home in Georgetown. Professor Walsh's first work on Porter, "Katherine Anne Porter's 'Noon Wine Devils'" appeared in 1968.
In the summer of 1958, Professor Walsh made his first trip to Mexico. This was to become an annual pilgrimage, a result of his love of the country and its people which grew from his interest in its art, literature, culture, and politics. In the summer of 1963, he directed Georgetown University's summer program at the Universidad Ibero-Americana in Mexico City. In Mexico City on April 15, 1963, he married Maria de los Angeles Garcia, who had been born and raised there. Their sons Thomas and Eugene were born in 1964 and 1967.
In the mid-1970s Professor Walsh decided to combine his interest in Mexico with his interest in Katherine Anne Porter. The result was his most important work, Katherine Anne Porter and Mexico: The Illusion of Eden (1992), a study of the influence of Mexico on Porter's life and work. He began the work with the assistance of a National Endowment for the Humanities Summer Stipend in 1976. In April 1976, he attempted to renew his acquaintance with Porter, who was then living in College Park, Maryland. That summer in Mexico City, he met Mary Louis Doherty, one of Porter's friends from Mexico in 1920-1921. Doherty urged Professor Walsh to renew his attempt to meet personally with Porter.
In June 1977, Professor Walsh called on Porter in College Park, presenting her with the bark painting by Inocencio Jimenez Chino which once hung in the Katherine Anne Porter Room in McKeldin Library. For a period of approximately eight months in 1977 and 1978, Professor Walsh visited Porter in her College Park apartment, interviewing her about her stays in Mexico and her Mexican works. With her permission, he also photographed her manuscripts and photographs having to do with Mexico. At this time, Porter had not yet conveyed these items to the University of Maryland because she first intended to write her own account of her Mexican experiences.
Although Porter's deteriorating health brought an end to these meetings, Professor Walsh continued his work on Porter, publishing ten articles between 1979 and 1991. These drew from his interviews with her as well as from her manuscripts. In the 1988-1989 academic year, Professor Walsh worked full-time on his monograph supported by a grant from the National Endowment for the Humanities. The completed manuscript was submitted to the University of Texas Press in April 1990. When he died on November 2, 1991, Professor Walsh's Katherine Anne Porter and Mexico was in press. He had been able to make final corrections to the galleys of the book.