Data For 1920-1936 Exclude Class I Switching And Terminal Companies; 1937-1942 Include Switching And Terminal Companies. Data For 1920-1934: Are Based On Daily Average Data; 1935-1942 Are Based On End-Of-Month Data. Source: Data Are Computed From Figures Found In Interstate Commerce Commission, Freight And Passenger Service Operating Statistics Of Class I Steam Railways In The U.S. For 1920-1934; Motive Power And Car Equipment Of Class I Steam Railways In The U.S For 1935-1942.
This NBER data series m01255 appears on the NBER website in Chapter 1 at http://www.nber.org/databases/macrohistory/contents/chapter01.html.
NBER Indicator: m01255
Release: NBER Macrohistory Database
National Bureau of Economic Research, Percent Serviceable of Total Freight Cars On Line, Class I Railroads for United States [M01255USM156NNBR], retrieved from FRED, Federal Reserve Bank of St. Louis https://research.stlouisfed.org/fred2/series/M01255USM156NNBR, February 14, 2016.