Release: NBER Macrohistory Database
Series Is Presented Here As Two Variables--(1)--Seasonally Adjusted Data, 1921-1937 (2)--Seasonally Adjusted Data, 1937-1943. Source: Computed By NBER By Subtracting (Serviceable Passenger Locomotives) From (Total Number Of Locomotives Assigned To Road Service).
This NBER data series m01266a appears on the NBER website in Chapter 1 at http://www.nber.org/databases/macrohistory/contents/chapter01.html.
NBER Indicator: m01266a
National Bureau of Economic Research, Average Number of Non-Serviceable Locomotives in Passenger Service for United States [M0166AUSM365SNBR], retrieved from FRED, Federal Reserve Bank of St. Louis; https://fred.stlouisfed.org/series/M0166AUSM365SNBR, October 21, 2016.