Data For 1921-1939 Were Converted From Shillings And Pence Per Quarter (480 Pounds) To Pence Per Bushel (Sixty Pounds) By NBER By Reducing To Pence And Dividing By Eight. Source: New York Produce Exchange, Data For 1887-1920: Annual Statistical Reports Of The Nype. Data For 1921-1939: Direct From Nype Files, Statistical Department.
This NBER data series m03034 appears on the NBER website in Chapter 3 at http://www.nber.org/databases/macrohistory/contents/chapter03.html.
NBER Indicator: m03034
Release: NBER Macrohistory Database
National Bureau of Economic Research, Ocean Freight Rates On Grain, New York To Liverpool [M03034M504NNBR], retrieved from FRED, Federal Reserve Bank of St. Louis https://research.stlouisfed.org/fred2/series/M03034M504NNBR/, October 7, 2015.