I've been meaning to write about this for a while, and finally had time to put it all together.
Not long after the Bitcoin software was released in January 2009, Hal Finney started running a node and mining.
The earliest Bitcoin network was maintained by just a handful of enthusiasts. Bitcoin got up and running because these people were willing to run nodes on their own computers.
For a real-time reference: $BTC is at 81563.87, down 0.93% over 24 hours.
If you have anything to add, let's talk in the comments.