Series Is Presented Here As Two Variables--(1)--Original Data, 1890-1944 (2)--Original Data, 1890-1961. Data Are For 280 Working Days Per Year. Source: U.S. Bureau Of Mines, Preprint From Minerals Yearbook 1959: Coal-Bituminous And Lignite, W.H. Young, R.L. Anderson, E.M. Hall; And Mineral Industry Surveys, Production Of Bituminous Coal And Lignite, Weekly Coal Report, August 24, 1962.
This NBER data series a01165b appears on the NBER website in Chapter 1 at http://www.nber.org/databases/macrohistory/contents/chapter01.html.
NBER Indicator: a01165b
Release: NBER Macrohistory Database
National Bureau of Economic Research, Calculated Capacity of Bituminous and Lignite Coal Mines for United States [A0165BUSA448NNBR], retrieved from FRED, Federal Reserve Bank of St. Louis https://research.stlouisfed.org/fred2/series/A0165BUSA448NNBR/, October 8, 2015.