Chicago is the leading grain market in the world. Its Board of Trade is the commercial center through which most of the trading in grains is done. D's 1600 members include brokers, commission merchants, dealers, millers, maltsters, manufacturers of corn products, and proprietors of elevators.
Grains are graded according to kind and quality and are sold usually 'Chicago weight, inspection, and delivery.' The standard forms of trading are: (a) Spot sales; that is, sales of grain already in Chicago in railroad cars or elevators for immediate delivery by order on carrier or transfer of warehouse receipt. (b) Future sales; that is, agreements for delivery later in the current or some future month. (c) Sales 'to arrive'; that is, agreements to deliver on arrival grain which is already in transit to Chicago or is to be shipped there within a time specified. On every business day sessions of the Board are held at which all bids and sales are publicly made. Spot sales and future sales are made at the regular sessions of the Board from 9.30 A.M. to 1.15 P. M., except on Saturdays, when the session closes at 12 M. Special sessions, termed the 'Call,' are held immediately after the close of the regular session, at which sales 'to arrive' are made. These sessions are not limited as to duration, but last usually about half an hour. Transactions are between members only; but they may trade either for themselves or on behalf of others. Members may also trade privately with one another at any place, either during the sessions or after, and they may trade with non-members at any time except on the premises occupied by D. In 1906 the Board adopted the 'Call' rule. Members were prohibited from purchasing or offering to purchase, during the period between the close of the Call and the opening of the session on the next business day, any wheat, corn, oats or rye 'to arrive' at a price other than the closing bid at the Call. The United States (P) filed suit against d and its executive officers and directors, to enjoin the enforcement of the Call rule, alleging it to be in violation of the Anti-Trust Law. D admitted the adoption and enforcement of the Call rule, and that its purpose was to promote the convenience of members by restricting their hours of business and to break up a monopoly in that branch of the grain trade acquired by four or five warehousemen in Chicago. The allegations concerning the purpose of establishing the regulation were stricken from the record. The case was rested upon the bald proposition, that a rule or agreement by which men occupying positions of strength in any branch of trade, fixed prices at which they would buy or sell during an important part of the business day, is an illegal restraint of trade under the Anti-Trust Law. The court enjoined them from enforcing the Call Rule. D appealed.