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 m01266b appears on the NBER website in Chapter 1 at http://www.nber.org/databases/macrohistory/contents/chapter01.html.
NBER Indicator: m01266b
National Bureau of Economic Research, Average Number of Non-Serviceable Locomotives in Passenger Service for United States [M0166BUSM365SNBR], retrieved from FRED, Federal Reserve Bank of St. Louis; https://fred.stlouisfed.org/series/M0166BUSM365SNBR, August 30, 2016.