Mr. Margolis was born in St. Paul on June 30, 1929, and received bachelor's and master's degrees from the University of Minnesota. In addition to freelancing for The Smithsonian magazine, Harper's, The New York Times Magazine and The New Republic, Mr. Margolis wrote books for children and adults. He wrote widely about migrant farm workers, the elderly, Indians and other minorities. He also wrote "All Their Days, All Their Nights," a prose poem about shack life in the United States, published by the Rural Housing Alliance (1971), and "Something to Build On," a report about self-housing, published by the American Friends Service Committee (1969). "Homes of the Brave," a report on migrant farm worker housing, was published in 1981 by Rural America, an advocacy group of which he was a founder and the first chairman. He is survived by his wife, Diane Rothbard Margolis of New Haven; two sons, Philip E., of Zurich, and Harry S., of Cambridge, Mass., and by a brother, Dr. Philip M., of Ann Arbor, Mich.