Shapiro wrote poetry in the Pacific Theater while he served there during World War II. His collection "V-Letter and Other Poems", written while Shapiro was stationed in New Guinea, was awarded the Pulitzer Prize for Poetry in 1945, while Shapiro was still in the military. Shapiro was American Poet Laureate in 1946 and 1947. (At the time this title was Consultant in Poetry to the Library of Congress which was changed by Congress in 1985 to Poet Laureate Consultant in Poetry to the Library of Congress.)