'The 4400' probably takes place in more than one of the alternate TV dimensions, but with variations, as was the case for the 'Star Trek' corner of Toobworld. As such, one of those alternate timelines would house the Bradbury Mars stories as told in episodes of 'Ray Bradbury Theater'.
In one ("The Long Years"), we see a Mars tombstone with the date "2007" inscribed on it. As the main character John Hathaway had been abandoned on the Red Planet for many years, and one of the crew members knew Hathaway's son in college twenty years before, it seems likely that in this variant of Maia's reformed timeline Mars was colonized even earlier than in 'The Martian Chronicles'.
And how could that have happened without interference by the faction from the future and the 4400?
Of course, as with 'The Martian Chronicles', it's a timeline that was wiped out in its own dimension once the 4400 children were removed from the past and returned to the present.
But at least we in the Real World know it did take place.
It once was and never will be. It's "neverwas".