The history of the postal system is inextricably tied to the history of transport. Advances in transportation technology have not only allowed people to travel farther and explore more territory, it also allowed the postal system to expand their influence over a larger area. As new inventions and discoveries shortened the time of travel, messages and letters began to reach distant recipients in lesser time, and the postal system became more efficient. By the time the first trans-pacific airmail was delivered, the postal service had tried every mode of transport available to man, including rockets.

The cover of a rocket mail delivered in the state of Sikkim, India, on 28 September, 1935. Photo credit: regencystamps.com