The Data Are Averages Of One Day A Week Quotations. 1905-1939 Prices Were Checked With Annual Reports Of The American Iron And Steel Institute (Aisi). Discrepencies Were Checked Against Weekly Figures In Iron Age. The Price For June, 1898, Was The "Lowest Price Ever Recorded" According To The 1914 Annual Report Of The Aisi, P.99. Source: Iron Age, January Review Issues, 1919, 1927, 1940, And The Following Monthly Issues.
This NBER data series m04160 appears on the NBER website in Chapter 4 at http://www.nber.org/databases/macrohistory/contents/chapter04.html.
NBER Indicator: m04160
Release: NBER Macrohistory Database
National Bureau of Economic Research, Wholesale Price of Soft Steel Bars for Pittsburgh, PA [M04160US38300M267NNBR], retrieved from FRED, Federal Reserve Bank of St. Louis https://research.stlouisfed.org/fred2/series/M04160US38300M267NNBR/, July 29, 2015.