Tarn published his first volume of poetry "Old Savage/Young City" with Jonathan Cape in 1964 and a translation of Pablo Neruda's "The Heights of Macchu Picchu" in 1966 (broadcast by the BBC Third Programme 1966), and began building a new poetry program at Cape. He left anthropology in 1967. From 1967-9, he joined Cape as General Editor of the international series Cape Editions and as a Founding Director of the Cape-Goliard Press, specializing in contemporary American Poetry with emphasis on Charles Olson, Robert Duncan, Louis Zukofsky and their peers and successors. In 1970, with a principal interest in the American literary scene, he immigrated to the United States as Visiting Professor of Romance Languages, Princeton University, and eventually became a citizen. Later he moved to Rutgers. Since then he has taught English and American Literature, Epic Poetry, Folklore and other subjects at the Universities of Pennsylvania, Colorado, and New Mexico.