Series Is Presented Here As Three Variables--(1)--Original Data, 1870-1926 (2)--Original Data, 1922-1942 (3)--Original Data, 1941-1955. Source: Data Were Computed By NBER From Seasonally Adjusted Data Of Orders For Passenger Cars, Freight Cars, And Locomotives Using Fixed Weights. For 1945-1951 Weights Were 16.1 For Passanger Cars, 36.7 For Locomotives, And 1 For Freights. Weights Were Derived From Interstate Commerce Commission Data On Value And Quantity Of New Equipment Installed For 1942-1955.
This NBER data series q06090c appears on the NBER website in Chapter 6 at http://www.nber.org/databases/macrohistory/contents/chapter06.html.
NBER Indicator: q06090c
Release: NBER Macrohistory Database
National Bureau of Economic Research, Index of Orders of Railroad Equipment for United States [Q0690CUSQ349NNBR], retrieved from FRED, Federal Reserve Bank of St. Louis https://research.stlouisfed.org/fred2/series/Q0690CUSQ349NNBR/, July 5, 2015.