If you could go back in time and watch an era of the mafia which would you go back and watch? For me I would like to go back and watch the start in the 20’s and 30’s and watch it progress all the way through the 80’s and just watch the way the mafia evolved right under the nose of the law enforcement of those days and just watch how they worked. It’s kind of internet reading all the biographies about the mafia espy the five families book 

the 50s or the 70s 

Ok Mr Clemente those are pretty interesting eras may I ask why

Honestly I am certainly not well versed in things of History, but I think that being a fly on the wall to watch the Aztec culture rise would be frightfully interesting.  I don't think I would have wanted to live it, but it would have been interesting to observe!

If we are restricting it to the mafia timeline as your post suggests, then I'd choose to observe the post-war boom of the late 40s to the 60s. Watching the mafia come in to its own at this time of economic boom, a long side the FBI becoming what we know of today under Hoover, along with the prestige of Lucky Luciano and others directly contributing to the allied war effort in the Sicilian landings and then returning afterwards has got to be one of the most interesting periods in the history of the Mafia.

If the is open to other time periods as your title suggests, then I would love to observe the rise and fall of the Celts. Very little is known of their history as the deliberately kept an oral rather than a written history so this is just a very large void with some hints a clues but no firm answers.

The 50s were an amazing era for the mafia shit the country in general it would be fun to see it play out and the 70s is in my opinion the true beginning of the end.