The Galactic Confederacy was a loosely-knit alliance of space-faring worlds.
Several millennia ago, when the Kryptonian people had constructed their massive World-Gate network and the time they had not started to encode their technology, which allowed many other races – having just discovered space-travel – to travel from one galaxy to the next. At first, Krypton had been hesitant to allow such use of their technology, due to their ancient law of noninterference, but after much debate, Krypton's wise Council of Twelve ruled that, since these other races were already capable of space-travel, they would eventually explore the rest of the universe and so allowing them to use the Gates would cause no harm. The development and fostering of trade and galactic commerce had commenced, which very soon led to the birth of the Confederacy. Though Krypton had never joined the Confederacy, it had retained some friendly relations with it.
During the Kree-Skrull War, the Galactic Confederacy remained neutral in the conflict between the Kree and Skrull Empires, but wary of the dangers of the major galactic powers and subsequently establishing a military footing should either empires would threaten the Confederacy. For this, the Confederacy entered a form of forced alliance with the intergalactic peacekeepers, the Green Lantern Corps, in opposing the Kree and Skrulls.
The Confederacy also upholds the Neutral Planets Treaty that forbids interference and exploitation in underdeveloped and non-space faring planets.
The Galactic Confederacy is apparently based on the United Planets that appears in the Legion of Super-Heroes comic books.