Source: Bureau Of Labor Statistics; 1919-1930 Data Are From Bls Bulletin No. 610, Pp. 101, 154-155; 1931-1934 Data Are From Bls Mimeographed Release, "Revised Index Numbers Of Factory Employment And Payrolls, " September 1938; 1935-1939 Data Are From Bls Mimeographed Monthly Release, May 1940; 1940-1942 Data Are From "Employment And Payrolls" And Monthly Labor Review.
This NBER data series m08132 appears on the NBER website in Chapter 8 at http://www.nber.org/databases/macrohistory/contents/chapter08.html.
NBER Indicator: m08132
Release: NBER Macrohistory Database
National Bureau of Economic Research, Index of Factory Payrolls, Cement for United States [M08132USM331NNBR], retrieved from FRED, Federal Reserve Bank of St. Louis https://research.stlouisfed.org/fred2/series/M08132USM331NNBR/, September 5, 2015.