Linked from
The 14 pages that link to Writing, each with the reason it gives.
LiteracyBroader topic: Writing is literacy’s expressive counterpart to reading.
CivilizationRelated: Writing enabled record-keeping and administration in some early states.
Tally marksRelated: Tally marks record quantities, but do not ordinarily encode spoken language.
History of communicationBroader topic: Writing made messages durable and separable from the speaker.