Series Is Presented Here As Two Variables--(1)--Seasonally Adjusted Data, 1866-1922 (2)--Original Data, 1920-1963. Data For 1907-1914 And 1916-1924 Are Identical To The Data In Series "Revenue And Non-Revenue Net Ton-Miles Of Freight Hauled" And Could Be Considered Additional Variable Segments. Data Exclude Switching And Terminal Companies. A Coal Strike Accounted For The Marked Decrease In April 1941. Source: Interstate Commerce Commission, "Revenue Traffic Statistics Of Class I Steam Railways In The United States"
This NBER data series q03003 appears on the NBER website in Chapter 3 at http://www.nber.org/databases/macrohistory/contents/chapter03.html.
NBER Indicator: q03003
Release: NBER Macrohistory Database
National Bureau of Economic Research, Railroad Freight Ton-Miles, Revenue for United States [Q03003USQ253NNBR], retrieved from FRED, Federal Reserve Bank of St. Louis https://research.stlouisfed.org/fred2/series/Q03003USQ253NNBR/, August 2, 2015.