Well, I think if a person was in America, and black, what was going on in 1968 would only be a part of the experience. Malcolm X - my hero - was assassinated in 1965, and the civil rights movement (in all its forms) was in motion.
Now, "Star Trek" wasn't a ratings behemoth at the time - it did eventually get cancelled due to ratings, after all - so I don't think the Kirk/Uhura kiss received Earth-shattering controversy. Just with the people who watched or knew of the show.
As aforementioned, while the supposedly 'first interracial kiss on television' wasn't exactly the first - America tends to focus on race whenever it involves a black person, usually a black male, opposite a non-black individual - as previously brought out, I'm sure it did have its share of controversy. This is in contrast to the many kisses between white men and Asian women on television before 'Plato's Stepchildren' (including the kiss between France Nuyen and William Shatner on "Star Trek," that aired after 'Plato's Stepchildren') that go without controversy.
It is a a double-standard I absolutely hate. And, that double-standard is still in place today, unfortunately.
As for the two Olympians that put up the 'black power' fist: San Jose State University has always had a nice statue commemorating the two men.