 In 1864, in the United States, wheat, corn, cattle, and pigs were widely traded using standard instruments on the Chicago Board of Trade (CBOT), the world's oldest futures and options exchange.Other food commodities were added to the Commodity Exchange Act and traded through CBOT in the 1930s and 1940s, expanding the list from grains to include rice, mill feeds, butter, eggs, Irish potatoes and soybeans.Successful commodity markets require broad consensus on product variations to make each commodity acceptable for trading, such as the purity of gold in bullion.