Back in 1977, when "Roots" ran the entire week for 8 nights, although it captivated viewers at the time, there was notably some drop off as the series progressed. However when it came time for the finale that Sunday night a week after it first premiered, anyone who had been faithfully following it, those who may have missed some during the week, and those who didn't even view it earlier, all tuned in to watch. And with that, this final installment broke all ratings records and held the coveted title of "most watched" episode of any type of all time for American television. In fact, it held that position for some 6 years until usurped by the finale of "M*A*S*H" which I very much recall watching myself in the dorm lounge on a 19" color TV (I was a senior in college at the time and only had a 13" B&W but was grateful for it...lol).
Although incorporating some well-needed humor courtesy of Ben Vereen's "Chicken George", the episode gave one a sharp contrast in how the son of a slave-owner could evolve into a fine gentlemen when removed from the discordant and dysfunctional life on a plantation, after having been sent overseas to live amongst those who started this institution but finally saw the error of their ways and banned such.
And with the backdrop of the Civil War and the roller coaster ride for the enslaved community, the sharp contrasts continue between elation and despair, particularly when in an echo of Part 3 where Kunta Kinte was brutally whipped, we find his great-grandson Tom facing the same sort of treatment - a purposeful but necessary commentary on how this ugly institution, despite being legally disbanded, would not go away quickly.
And with a little bit of a Hollywoodism that ends the miniseries on a more positive note, "Chicken George" is able to bring his brood out of Virginia and off their nightmarish plantation, and into Tennessee to live and work on land he purchased himself after having been freed - the land bought from the winnings of his occupation as cock trainer and fighter.
And so concluded a historical and ultimate historic (from the television perspective) miniseries that would define the potential of the miniseries, beyond what its predecessor "Rich Man, Poor Man" could ever do.