In the beginning, technical writers had limited tools and delivery systems. Some of these systems can still be seen in an animal husbandry manual from 13,000 BC, found in the caves at Lascoux, France.
Writers in Egypt progressed to using hieroglyphics.
The oldest glossary identified so far is the Rosetta Stone, from 196 BC.
In the middle ages, the Middle Ages, most of the technical writers were monks, who created illuminations. This illustration is from a health care manual.
With the invention of the printing press, the technical writing field advanced steadily. Earlier in the twentieth century, the typewriter made it easier to create readable drafts.
Finally, in the late twentieth century, the word processor, the increasing availability of personal computers, and the World Wide Web brought an increasing number of ways to present technical information.
Note: This history is under construction. I need to acknowledge the contributions of bards and other communicators of oral history and instruction.