According to the timeline published in the Judge Dredd RPG, reprinted on this very website, Mega-City 1 was built between 2023 and 2031 - at which point Fargo was the first chief Judge.
President Booth started the Atomic Wars in 2070, a few years after Judge Dredd was cloned (in 2066).
President Booth started the Atomic Wars in 2070, a few years after Judge Dredd was cloned (in 2066).
Link: Timelines