Humans

Only a few thousand remained after nuclear devastation on earth. With so much of the planet uninhabitable due to radiation, these humans survived underground until it was safe to come back up again. They started building towns in the area known as the Outskirts and even settled into the four districts of Diamond City. Five hundred years later, many became Enhanced to fight the Overseers and allegedly drive away the Lolligo, the original founders of the Diamond City districts.