Source: Bureau Of Labor Statistics, 1919-1934 Data Are From Bls Mimeographed Release, September 1938; 1935-1939 Data Are From Bls Mimeographed Release, May 1940; 1940-1942 Data Are From "Employment And Payrolls" And Monthly Labor Review.
This NBER data series m08073 appears on the NBER website in Chapter 8 at http://www.nber.org/databases/macrohistory/contents/chapter08.html.
NBER Indicator: m08073
Release: NBER Macrohistory Database
National Bureau of Economic Research, Index of Factory Payrolls, Iron and Steel Products for United States [M08073USM331NNBR], retrieved from FRED, Federal Reserve Bank of St. Louis https://research.stlouisfed.org/fred2/series/M08073USM331NNBR/, July 6, 2015.