but it still took days or weeks for the actual bushels of grains to travel there so buyers and sellers started completing their transactions over the telegraph because it was faster
I think this is extremely interesting. The telegraph at this time was being used for buyers to essentially preorder grain, to ensure they maintained the current price it was. This almost reminds me of a combination of modern actions of buying stock and online shopping. As stock fluctuates in price constantly the price of grain back then seemed to as well, therefore by placing a transaction over the telegraph these buys claimed their price and items. Similar to online shopping in how the buyers are purchasing an item not yet in their sites but only exists in theory. By fronting the money or the intention of payment they are reserving the right to the item before it is in their possession.