A decade ago, the hashtag (as we know it) was born with a single tweet:

how do you feel about using # (pound) for groups. As in #barcamp [msg]?

— ⌗ChrisMessina (@chrismessina) August 23, 2007

What’s interesting is that the discussion had actually started earlier than that, with Messina pitching the idea to the early Twitter team directly, as Biz Stone blogged today:

His proposal was simple, useful, and fun—just like Twitter. Because brevity is essential on Twitter, he suggested using the “pound” or “hash” character common on phones (this was pre-iPhone) to create groups of related Tweets. It was an undeniably elegant proposal, but I really needed to get back to work. I turned back to my computer screen to help get Twitter back up and running, hurriedly ending the conversation with a sarcastic, “Sure, we’ll get right on that.”

It took them a few years to actually “get right on that” and integrate it into the service formally.

Messina himself has bloomed about what his creation has meant to him:

A hashtag is not a place and is not property (despite some ill-advised attempts to introduce controls on participation and use of certain tags). The lifespan of a hashtag lasts only as long as people animate it with their attention and contributions. Hashtags that no longer inspire participation gradually fade from the collective consciousness. This is a good and natural thing.

A few people need to be reminded that you can’t own a hashtag…