I must disagree. The ACLU gained traction in MLK's day, the 50s and 60s, as great liberators of oppressed blacks; but the ACLU always has been a communist organization. They used the vulnerable black community to further the rest of their agenda, just as Democrats have been using blacks ever since with a “the soft bigotry of low expectations.”
Blacks were the fall guys for white communists; and now that their reputations and enclaves are in ruins, the socialist/communists are using the mentally ill (mass shooters and the sexually deranged). Trump was the first president since Eisenhower to genuinely acknowledge blacks' capabilities, call out the genuine needs of AA communities—tools to build social and economic freedoms and responsibilities—and address them without pandering.
As for what has happened with American blacks since the Civil Rights movement, it was predictable; in 1967 the great social philosopher Eric Hoffer wrote, in The Temper of Our Time,
“Every great cause begins as a movement, becomes a business, and eventually degenerates into a racket.”
Reasonable men may disagree on any number of topics.
If Michael King was a tool of the left, IMO he was a willing tool who knew he was being used.
In any case, you don’t seem to be disagreeing with me that the practical result of the so-called “civil rights movement” has been societal disaster.