He trained in ballet under Catherine Littlefield, danced at the 1939 New York World's Fair, and toured with the George Balanchine company in South America in 1941.

When he met author Truman Capote in 1948, Dunphy had written John Fury, a well-received novel, and was just getting over a painful divorce from McCracken.

The couple drifted more and more apart in the later years and their relationship turned platonic after Truman’s story "La Côte Basque, 1965" was published in Esquire in 1975.

We were always dreaming away from wherever we were, thus repeating the pattern that had commenced in childhood, when one’s need to escape from one’s own kind was so savage, so burning in its intensity, that had either of us stayed home, he would certainly have perished.

John Fury (Harper and Brothers, 1946) is the story of an Irish working-class man who moves from a happy marriage to an unpleasant one in a life of poverty, hard work, and frustration, where his only reprisal is anger.

According to the website of Ayer Company Publishers, a reprint publisher of rare and hard to find titles, Mary McGrory praised the book in The New York Times at the time of publication:It adds up to a remarkable first novel, warm and strong, its unflinching realism saved from brutality by the author's compassion and restraint ... What Betty Smith did tenderly for Brooklyn, James T. Farrell harshly for Chicago and, most recently, Edward McSorley in his moving Our Own Kind for Providence, Dunphy does for Philadelphia.

Other Dunphy novels are Friends and Vague Lovers (Farrar, Straus and Young, 1952), Nightmovers (William Morrow, 1967), An Honest Woman (Random House, 1971), First Wine (Louisiana State University Press, 1982) and its sequel, The Murderous McLaughlins, (McGraw-Hill, 1988).