“Until recently apparently no serious attempt had been to make a comprehensive examination into the origins and history of commercial instruments or to explain the special doctrines attached to negotiability….
“The bill of exchange, it is said, developed as a bit of machinery to give effect to the medieval contract of cambium which was concerned with the special case of the exchange of money for money. With the growth of foreign trade the difficulties and dangers of payments multiplied. Naturally those whose business it was to exchange monies were resorted to in this connection. They, in turn, out of necessities of the situation, particularly the danger involved in transporting valuables, were driven to adopt new means or to adapt old agencies to avoid these risks. Out of this no doubt our modern bill of exchange developed.”
Aigler, Ralph W. "Commercial Instruments, the Law Merchant and Negotiability." Minn. L. Rev. 8, no. 5 (1924): 361–78.