To unite the independent colony worlds and promote interstellar trade, the alliance offered many benefits to member planets. Some worlds held out against the confederation and became known as Associated Planets, like Sorelledolce. The official currency of the Hundred Worlds was the starcount.
Members of the Hundred Worlds were represented in the Congress, and held equal sway with other members. Planets with a high enough population could apply to send colonizers to uninhabited planets.
The confederation of planets known as the Hundred Worlds was presumably established alongside the founding of Starways Congress.