Evanston was an old timber-mill country town in America that was abandoned when the milling business went under. It remained deserted until Jordan Collier, after distributing promicin to the world, united 100 P positive people, now fugitives from the government for taking the illegal substance, and settled in the town, restoring it to its former glory and created a peaceful and stable utopia. Collier, however, planned to eventually move on from Evanston as he didn't intend it to be a permanent settlement.
When NTAC Agent Tom Baldwin came to town in search of Kyle, who had earlier decided to join Collier's movement, Collier knew the time had come to move on and he led his followers, including Kyle and Isabelle Tyler to Seattle, where they established Collier's intended permanent settlement; Promise City.