Talk:Grounders/@comment-26832374-20150729031817/@comment-26247132-20150729044936

The Grounders had to take shelter somewhere from the apocalypse. Let's take the DC subway system as an example and say they had turned a subway station into a make-shift underground bunker. The only limitation for the amount of people there is to have enough supplies to sustain a population for fifty years (because, according to Dante, that's how long it took before they were able to return to the surface). If they had time to gather resources prior to the apocalypse, then they could have supported quite a substantial population with each station being like a village.

The subway stations are connected by the subway lines. This means you can connect up with other survivors who found their way to other stations and you could trade with them, exchanging food, supplies, and even reproductive partners. BUT! This also means someone else can come in and raid your village/tribe so you need to protect it some way. Supplies are limited and if someone else didn't prepare as well as you, they will want to take what is yours to survive for themselves. And thus, the fighting starts. Stations/villages will pick sides and eventually, either only one side is left or they have enough supplies for everyone left alive (and are willing to share). And that is how a Clan is born.

Fifty years later, the grandchildren and great-grandchildren of the original survivors make their way back up to the surface and discover they're not the only ones who made it. Others have survived in other areas (different subway lines or different bunkers or caves or whatever your imagination comes up with). These people have also formed clans of their own. And that is how the 12 Clans exist.