After 1961, Monthly Data No Longer Published, Only Quarterly Data Available. Source: Interstate Commerce Commission., Computed By NBER From Original Data Of Total Operating Revenues Series Minus Total Operating Expenses Of Railroads Series, Class I Railroads
This NBER data series q09026 appears on the NBER website in Chapter 9 at http://www.nber.org/databases/macrohistory/contents/chapter09.html.
NBER Indicator: q09026
Release: NBER Macrohistory Database
National Bureau of Economic Research, Net Revenue From Railway Operations, Class I Railroads for United States [Q09026USQ144NNBR], retrieved from FRED, Federal Reserve Bank of St. Louis https://research.stlouisfed.org/fred2/series/Q09026USQ144NNBR/, September 3, 2015.