The- futures market as we know it today originated around 1850 when a canal linking the Illinois River with Chicago was constructed. This canal enabled country merchants to purchase grain from farmers and ship the grain to Chicago via barges. However, corn could only improve from farms to country merchants during the winter, when country roads were passable. These country merchants were then forced to hold the corn until spring when the canal opened. From the time the country merchants received and paid for the corn from the farmers and the canal opened in the spring, considerable price changes could occur.
O'Conner, Carl and Winkler, Charles, "A Class Exercise In Futures Market Trading" (1974). Economic Staff Paper Series. 170.