Following the Tzenkethi War, the Terran Federation entered a small economic downturn. In response, the Senate announced that funding will go towards exploration and discovering new worlds to colonize.
In 2251, a planet rich in mineral resources was discovered and colonized shortly after. After two years, the planet, named Babylon, began to serve as a beacon of hope for those who lost their homes to the Tzenkethi. The success of Babylon led to the colonization of other worlds such as Carthage and Holland. During this Great Breakout, over seventy worlds were colonized by chartered members. However, the massive expansion ended in 2285 when a group of Senators from the Heart Worlds tried to use the money used in expansion to improve the economics of the colonies they had.
Even after the massive expansion, several more colonies were charted and settled upon. While some barely grew beyond their original functions, a few settled worlds such as Agamar and Onderon become prosperous colonies.
During the Gilded Age, the income from newly settled colonies and outposts helped to fuel a massive economic boom.
In the Heart Worlds, Senators became increasingly xenophobic following the Tzenkethi War. As a result, colonial governments and citizens attempted to discourage what they called Aliens from voting in colonial and presidential elections, or applying for jobs in Human only neighborhoods.
However, the Humans of the then recently settled Middle Colonies seemed to be more tolerant of Non-Humans and did nothing to discourage them. The growing number of Middle Colonies led to their senators gaining a massive majority in the Senate and the continual quieting of the voices of Heart Worlds senators.
During the end of the Great Breakout, several senators and governors in the Heart Worlds had begun to "discourage" non-humans from taking jobs in mostly human neighborhoods and voting in Colonial and Presidential elections. This prompted several humans and non-humans to leave the Heart Worlds for the Middle Colonies.