Let's pause here for a second. MLK and the civil rights movement occurred decades before the term political correctness was even invented. So, ostensibly, there is no "different interpretation" of political correctness... there are actions of one era, and then this thread dedicated to discussing an entirely separate concept.
Surely, isn't that why that era is not related to the current discussion of political correctness? You're talking about movements and concepts that were starkly different -- the term political correctness didn't exist, the racists were still part of the Democrat party, and "progressive" people were fighting for integration/equality.
Now, "political correctness" is a modern term and phenomena that is used to describe the attempted censorship of ideas/expression that run against a subjective "correct" view of politics. Now, it's "politically correct" to
call for segregated housing or
bully anyone as long as they're on the "incorrect side" or
ban anything that anyone might find mildly upsetting. It seems to be completely counter purpose and spirit of the civil rights movement; and accordingly I'm not sure how it's 'on topic' for a thread discussing something completely different than what Legacy just posted. I'm not sure how you even compare/contrast between the two in an intellectually honest fashion when one is so far removed from the other.