Series Is Presented Here As Two Variables--(1)--Seasonally Adjusted Data, 1919-1942 (2)--Original Data, 1939-1956. This Index Was Discontinued In September 1942 And Superseded By One That Represents The Number Of Production Workers In The Industry, Starting In 1939. Both Segments Are Considered Roughly Comparable. Source: Federal Reserve Board, Bulletins, For 1919-1933 Data: October 1938; For 1934-1942 Data: October 1939 And Following Monthly Issues.
This NBER data series m08101a appears on the NBER website in Chapter 8 at http://www.nber.org/databases/macrohistory/contents/chapter08.html.
NBER Indicator: m08101a
Release: NBER Macrohistory Database
National Bureau of Economic Research, Index of Factory Employment, Leather and Manufactures for United States [M0801DUSM331SNBR], retrieved from FRED, Federal Reserve Bank of St. Louis https://research.stlouisfed.org/fred2/series/M0801DUSM331SNBR/, August 31, 2015.