Content: 1826-44 And 1920-35: Great Britain Only; 1845-1912: Great Britain And Ireland (In 1844, Gt. Britain: 192 Miles, Ireland, 12 Miles) Source: 1826-48: H. G. Lewin, "Early British Railways, " P. 186 And T. Tooke And W. Newmarch, "A History Of Prices, " Vol V, P. 352; 1849-68, 1872-1912, 1920-35: Parliamentary Papers, "Railway Returns By The Board Of Trade, " 1870, P.Lix, 1871, P.88, 1872, Pliv,1913, Pp.Xiii And Xx, And Later Issues Including 1932, P.18.
This NBER data series a02085 appears on the NBER website in Chapter 2 at http://www.nber.org/databases/macrohistory/contents/chapter02.html.
NBER Indicator: a02085
Release: NBER Macrohistory Database
National Bureau of Economic Research, Increases In Length of Railway Line Opened For Traffic for Great Britain [A02085GBA374NNBR], retrieved from FRED, Federal Reserve Bank of St. Louis https://research.stlouisfed.org/fred2/series/A02085GBA374NNBR/, June 30, 2015.