Alberto Pedro Calderon was one of the leading mathematicians of the 20th century. Alberto Pedro Calderon was born on September 14, 1920, in Mendoza, Argentina. He studied civil engineering at the University of Buenos Aires and graduated in 1947. Between 1989 and 1992, he was a professor emeritus, with a post retirement appointment at that same institution. In 1979 he was awarded the Bôcher prize for a paper on the Cauchy integral on Lipschitz curves. In 1989 he shared the Mathematics Prize of the Wolf Foundation of Israel with his American colleague John W. Milnor. He received innumerable other honors around the world. The American Mathematical Society honored Calderon again with the prestigious Steele Prize in 1989, and former U.S. president George Bush, in granting him the 1991 National Medal of Science, cited "his ground-breaking work on singular integral operators leading to their application to important problems in partial differential equations." He died on April 16, 1998 in Chicago, Illinois, United States.