In 2078, Terra Nova became the first planet outside the Sol system to be colonized by Humans. After several years of success with the colony, Earth decided to send more colonists to the planet, which didn't meet with the approval of the Novans. Shortly after, the colony was struck by meteors which unleashed massive radiation in the planet's atmosphere. Survivors were able to escape underground, but communications with Earth were cut-off, and the colony was officially declared lost, causes unknown.
The colonists were eventually rediscovered in 2151 by Captain Jonathan Archer and the crew of the Enterprise (NX-01). While the descendants of the colonists were initially untrusting of the Enterprise crew, they soon agreed that Earth was not responsible for the meteor strikes, and decided to work to relocate their populace to a new uncontaminated area. (ENT episode: "Terra Nova")
Logan City soon became the capital city of the colony, and following admittance into the United Federation of Planets in 2178, the planet's inhabitants increased to around 374,000 by 2376. (ST reference: Star Charts)