for me one event that will mark this period are 'our' first steps into space.
other than that i'm a little bit more pessimistic ...

i would be tempted to talk about human rights but that started a few centuries ago and they're not likely to be really universal for a few centuries.

we still have wars, famine, slavery, genocide, dictatorships .

another possibility is that this part of history will have been rewritten or completely erased