Data For 1921-1928 And 1933-1943 Include Switching And Terminal Companies; Data For 1929-1932 Exclude Switching And Terminal Companies. Data Include Construction Allowances In Train And Engine Services. Source: Interstate Commerce Commission, Bureau Of Statistics
This NBER data series m08152 appears on the NBER website in Chapter 8 at http://www.nber.org/databases/macrohistory/contents/chapter08.html.
NBER Indicator: m08152
Release: NBER Macrohistory Database
National Bureau of Economic Research, Straight Time Man-Hours Worked, All Employees On Hourly Basis, Class I Railroads for United States [M08152USM443NNBR], retrieved from FRED, Federal Reserve Bank of St. Louis https://research.stlouisfed.org/fred2/series/M08152USM443NNBR/, July 31, 2015.