That was a watershed example. The white elite of one of the leading cities of the South, honoring MLK in a mixed race event, shows where the cultural zeitgest was.
There was a very large and clear trend toward desegregation in the South that had been in place since long before the passing of the Civil Rights Act. You note the existence of private segregation as evidence of the lack of a trend, when it is no such thing. A trend doesn't imply that the parameter subject to the trend is, at all points within that trend, at its final state.
>>These covenants (like all covenants that run with the land) bound even non-signers to them; they were intended to be in place forever.
Legal means of overturning these covenants could have been created without the Civil Rights Act, and its injection of the state's apparatus of violence onto private interactions, and instituting such legal means could have been done far more easily than instituting the CRA, as land has always been a more legitimate object of state control than other forms of private property - especially in this case, where the state's intervention would have simply absolved non-signers from having to honor a disembodied contractual clause.
>>Claiming that if things were just left to their own devices, racial harmony and desegregation would eventually result is wishful thinking, and is supported neither by history nor the countless examples of ongoing racism throughout the world where relatively free markets exist and anti-segregation laws do not.
You're not informed on the history. There are profound historical examples of desegregation occuring in the wake of the abolition of mandated segregation. The best example is the Northern States, which had an extremely racist culture at one time too, contrary to what some may believe on account of their earlier rejection of slavery and their war to end it.
Every single strongly segregationist society has only ever persisted in such a state with the aid of ideocratic anti-market laws that instituted mandatory segregation, and there's a reason for that: a free society is not in its majority, inherently segregationist. Such a state of interaction is unnatural and inefficient, and in the presence of a right to voluntary interaction in both the civil and economic sphere, is gradually reduced to nothing but the fringes.