DIGITAL THE EXCHANGE COMMUNICATION FALL 2021 Pony Express Telephone The Internet 1860 1876 1980 Transcontinental Mobile Phone Now Telegraph 1861 1973 2021 Over the past few centuries, two-way communication has evolved from binary code and horse-drawn mail services to countless History of Digital messaging apps at our fingertips. As Salesforce moves into a Slack- first environment, let’s take the time to reflect on the history of 21 Communication interpersonal digital communication.