Series Is Presented Here As Two Variables--(1)--Original Data, 1850-1919 (2)--Original Data, 1905-1958. Source: U.S. Bureau Of Mines, Mineral Resources, 1924, Pt. Ii, Pp. 588-589.
This NBER data series a01118 appears on the NBER website in Chapter 1 at http://www.nber.org/databases/macrohistory/contents/chapter01.html.
NBER Indicator: a01118
Release: NBER Macrohistory Database
National Bureau of Economic Research, Bituminous Coal Production for United States [A01118USA448NNBR], retrieved from FRED, Federal Reserve Bank of St. Louis https://research.stlouisfed.org/fred2/series/A01118USA448NNBR/, December 1, 2015.