Source: Chicago Board Of Trade, Annual Reports; Crops And Markets.
This NBER data series m01046 appears on the NBER website in Chapter 1 at http://www.nber.org/databases/macrohistory/contents/chapter01.html.
NBER Indicator: m01046
Release: NBER Macrohistory Database
National Bureau of Economic Research, Sheep Receipts for Chicago, IL [M01046US16980M599SNBR], retrieved from FRED, Federal Reserve Bank of St. Louis https://research.stlouisfed.org/fred2/series/M01046US16980M599SNBR/, July 31, 2015.