The study of linguistics is fascinating…and one of the most difficult careers I can think of. Messengers, of various different spoken languages, would travel in person with both spoken communications and those written down. Writing began somewhere between Sumer and Egypt (let the historians fight that one out), and the first examples were non-alphabetical and looked like this:

It’s called cuneiform, and it was used mainly for administrative reasons (tracking commerce) and religious purpose, like keeping track of seasonal ceremonies. As a form of communication, it was used for official documents and personal correspondences between kingdoms. They used clay tablets and pressed their stylus into wedge-shaped forms. They also used leather skins for documentation, but due to its easy-to-decompose nature, it’s hard to find examples in the archaeological record.

Thoth – Egyptian God of the Scribe

In Egypt, hieroglyphic writing had magical or supernatural associations, and the people who could read and write were a special class of citizen. In Mesopotamia, writers—most likely a male profession—underwent intense training before they could call themselves dubsar (Scribe).

Whichever way you look at it – writing was preserved for the elite, and it was used by those in power to:

1. Justify their rule.
2. Increase their wealth.

Preserving cultural memory (a.k.a. history), didn’t really develop until Herodotus in 600 BCE.

For more information on this fascinating topic, check out this website: Ancient Scripts

As for crows, or pigeons, or any other bird-delivery device; they were devilishly tricky to train, and even harder to prove when the practice started. Since early writing was on heavy tablets, my bet is on the human mailman.