Series Is Presented Here As Two Variables--(1)--Seaonally Adjusted, 1917-1933 (2)--Seasonally Adjusted, 1932-1940. NBER Compiled Weighted Totals Of Seasonally Adjusted Data For 28 Of Their Food And Tobacco Series (Including 3 Import Series) For 1920-1940. From 1917-02/1918, Only 19 Series Were Available And From 03/1918-12/1919, 25 Series Were Available. The Data For The 19 Series Were Raised To The Level Of The 25 By Multiplying By 107.6 (The First Raising Factor Was Obtained From The Year 03/1918-02/1919 And The Second From The Year 1920). Source: See Note Below
This NBER data series m01191bb appears on the NBER website in Chapter 1 at http://www.nber.org/databases/macrohistory/contents/chapter01.html.
NBER Indicator: m01191bb
Release: NBER Macrohistory Database
National Bureau of Economic Research, Index of Commercial Production of Foodstuffs and Tobacco Products for United States [M011BBUSM331SNBR], retrieved from FRED, Federal Reserve Bank of St. Louis https://research.stlouisfed.org/fred2/series/M011BBUSM331SNBR/, August 29, 2015.