Series Is Presented Here As Three Variables--(1)--Seasonally Adjusted Data, 1919-1924 (2)-- Seasonally Adjusted Data, 1923-1942 (3)--Original Data, 1939-1956. This Variable Refers Only To The Automobile Industry; The Following Variables In The Series Refer To The Broader Category Of Transportation. Source: Data For 1919-1922 Was Furnished By The Federal Reserve Board; Data For 1923-1924 Is From Federal Reserve Bulletin, October 1938.
This NBER data series m08019a appears on the NBER website in Chapter 8 at http://www.nber.org/databases/macrohistory/contents/chapter08.html.
NBER Indicator: m08019a
Release: NBER Macrohistory Database
National Bureau of Economic Research, Index of Factory Employment, Automobile for United States [M08F9AUSM331SNBR], retrieved from FRED, Federal Reserve Bank of St. Louis https://research.stlouisfed.org/fred2/series/M08F9AUSM331SNBR/, July 5, 2015.