This Series Ends On The 1923-1925=100 Base, And The New Revised Series Starts In 1939 On A 1939 Base. Source: For 1919-1930, Bureau Of Labor Statistics, Bulletin 610; For 1931-1934, Bureau Of Labor Statistics, Mimeographed Report, September, 1938; For 1935-1939, Bureau Of Labor Statistics, Mimeographed Report, May, 1940; For 1940, Bureau Of Labor Statistics, "Employment And Payrolls".
This NBER data series m08120 appears on the NBER website in Chapter 8 at http://www.nber.org/databases/macrohistory/contents/chapter08.html.
NBER Indicator: m08120
Release: NBER Macrohistory Database
National Bureau of Economic Research, Index of Factory Payrolls, Dyeing and Finishing for United States [M08120USM331NNBR], retrieved from FRED, Federal Reserve Bank of St. Louis https://research.stlouisfed.org/fred2/series/M08120USM331NNBR/, July 28, 2015.