Series Is Presented Here As Two Variables--(1)--Original Data, 1919-1946 (2)--Original Data, 1933-1955 Data Represent Deliveries To Fabricators Of All Refined Copper Regardless Of Origin, Beginning In 1947; Previously Foreign New Material Is Included Only If Duty Free. Data Include Copper Released From The National Stockpile In Certain Months And Beginning With March 1952 Copper Imported From Nonmembers Of The Copper Institute. Deliveries To The National Stockpile Are Not Included. Beginning In 1947, Figures Include Refined Copper From Dutiable Foreign Material. According To "U.S. Foreign Commerce And Navigation", 1946, Only About Six Percent Of Such Imports Were Dutiable In 1946. During 1947 The Tariff On Copper Was Suspended (See Survey Of Current Business, 1955 Supplement, Note 7 To P. 159); Therefore Figures Before And After 1947 Are Considered Comparable. Source: American Bureau Of Metal Statistics Yearbook, 1947 And Following Issues; Metal Statistics, 1941 And Following Issues. This NBER data series m01177b appears on the NBER website in Chapter 1 at http://www.nber.org/databases/macrohistory/contents/chapter01.html. NBER Indicator: m01177b