Kind of depends on how you define "State." There were really only 3 entities in the Periphery that ComStar put on the map as kind of nations.. The Elysian Fields, Oberon Confederation and The Greater Valkyrate.
Oberon VI fell to the Clans in September of 3049, The Greater Valkyrate in September of the same year most likely (Jade Falcon Sourcebook doesn't have the same details for the Periphery planets.
The Elysian fields didn't have a military, and was skipped over at first, and the Clans only landed on the planet after rumors of a Star League base on one of the planets cropped up. So you're looking again at August and September most likely.