1945: Houghton Mifflin Poetry Prize Fellowship

1947: Guggenheim Fellowship

1949: Appointed Consultant in Poetry at the Library of Congress

1950: American Academy of Arts and Letters Award

1951: Lucy Martin Donnelly Fellowship, Bryn Mawr College

1953: Shelley Memorial Award

1954: Elected to lifetime membership, National Institute of Arts and Letters

1956: Pulitzer prize for Poetry

1960: Chapelbrook Foundation Award

1964: Academy of American Poets Fellowship

1968: Fellow of the American Academy of Arts and Sciences

1968: Ingram-Merrill Foundation Grant

1969: National Book Award

1969: The Order of the Rio Branco (awarded by the Brazilian government)

1974: Harriet Monroe Poetry Award

1976: Books Abroad/ Neustadt International Prize

1976: Elected to the American Academy of Arts and Letters

1977: National Book Critics Award

1978: Guggenheim Fellowship