NBER Checked Data By Dividing Figures For Freight Earnings By Figures For Ton-Miles For The Grouping Of Seven Railroads. The Figure For 1866 Presented Here (2.544) Was Computed By NBER; It Was Given In The Source As 2.503. Data Were Revised In 1887, But Are Presented Here As One Continuous Variable. Figures For 1887 And 1889 More Comparable To Earlier Data Are .718 And .696 (This Figure Was Computed By NBER As The Source Gave .609). Source: Poor'S Manual Of Railroads, 1888, Pp. Xxvii-Xxix; 1889, P. Viii; 1890; 1891; 1892.
This NBER data series a03003h appears on the NBER website in Chapter 3 at http://www.nber.org/databases/macrohistory/contents/chapter03.html.
NBER Indicator: a03003h
Release: NBER Macrohistory Database
National Bureau of Economic Research, Revenue Per Freight Ton-Mile, Seven Railroads for United States [M0303HUSA259NNBR], retrieved from FRED, Federal Reserve Bank of St. Louis https://research.stlouisfed.org/fred2/series/M0303HUSA259NNBR, February 8, 2016.