Complex sentence: He became chief poetry reviewer for "The Nation" (1940), in 1941-2 he served as publications director in the Office of the Coordinator of Inter-American Affairs, and was then invited to be resident fellow at the Library of Congress.
Split into simpler sentences: He became chief poetry reviewer for "The Nation" (1940). In 1941-2 he served as publications director in the Office of the Coordinator of Inter-American Affairs, and was then invited to be resident fellow at the Library of Congress.