A Brief History
In the 1840s, Chicago had become a commercial center with railroad and telegraph lines connecting it with the East. Around this same time, the McCormick reaper was invented which eventually lead to higher wheat production. Midwest farmers came to Chicago to sell their wheat to dealers who, in turn, shipped it all over the country.
He brought his wheat to Chicago hoping to sell it at a good price. The city had few storage facilities and no established procedures either for weighing the grain or for grading it. In short, the farmer was often at the mercy of the dealer.
1848 saw the opening of a central place where farmers and dealers could meet to deal in "spot" grain - that is, to exchange cash for immediate delivery of wheat.