and the University of Buenos Aires. Calderón together with his mentor and collaborator Zygmund, maintained close ties with Argentina and Spain, and through their doctoral students and their visits, strongly influenced the development of mathematics in these countries. 1947 - 1950 Rockefeller Foundation Fellow, University of Chicago 1950 - 1953 Visiting Associate Professor, Ohio State University, Columbus, Ohio 1953 - 1955 Member, Institute for Advanced Study, Princeton, New Jersey 1955 - 1959 Associate Professor, Massachusetts Institute of Technology 1959 - 1968 Professor, University of Chicago 1968 - 1972, Louis Block Professor of Mathematics, University of Chicago 1972 - 1975 Professor, Massachusetts Institute of Technology 1975 - 1985, University Professor of Mathematics, University of Chicago 1975 - death, Honorary Professor, University of Buenos Aires He was also visiting professor at universities including the University of Buenos Aires, Cornell University, Stanford University, National University of Bogotá, Colombia, Collège de France, Paris, University of Paris (Sorbonne), Autónoma and Complutense Universities, Madrid, University of Rome and Göttingen University. Awards and honors Calderón was recognized internationally for his outstanding contributions to Mathematics as attested to by his numerous prizes and membership in various academies. He gave many invited addresses to universities and learned societies. In particular he addressed the International Congress of Mathematicians: a) as invited lecturer in Moscow in 1966 and b) as plenary lecturer in Helsinki in 1978. The Instituto Argentino de Matemática (I.A.M.), based in Buenos Aires, a prime research center of the National Research Council of Argentina (CONICET), now honors Alberto Calderón by bearing his name: Instituto Argentino de Matemática Alberto Calderón. In 2007, the Inverse Problems International Association (IPIA) instituted the Calderón Prize, named in honor of Alberto P. Calderón, and awarded to a "researcher who has made distinguished contributions to the field of inverse problems broadly defined". Academies 1958 Member, American Academy of Arts and Sciences, Boston, Massachusetts 1959 Correspondent Member, National Academy of Exact, Physical and Natural Sciences, Buenos Aires, Argentina 1968 Member, National Academy of Sciences of the U.S.A. 1970 Correspondent Member, Royal Academy of Sciences, Madrid, Spain 1983 Member, Latin American Academy of Sciences, Caracas, Venezuela 1984 Member, National Academy of Exact, Physical and Natural Sciences, Buenos Aires, Argentina 1984 Foreign Associate, Institut de France, Paris, France 1984 Member, Third World Academy of Sciences, Trieste, Italy Prizes 1969 Latin American Prize in Mathematics, awarded by IPCLAR (Instituto para la Promoción de las Ciencias, Letras y Realizaciones),