This work assembles comparable input-output tables for 1939, 1947, and 1958 along with auxiliary information on labor, capital, and final demand for 1939, 1947, 1958, and 1961--data that have not in the past been readily accessible to most students and business analysts. Graphic forms of presentation liberally supplement the basic tables. The study shows how technological change has affected industrial specialization, as well as direct primary inputs, and how these components of change are interrelated.