Was Martin Luther King a freemason? If so, what were some clues?

it does seem to have been Dr. King's intention to become a Mason.  Both his father and his grandfather were Masons. He was arranged to become a Freemason upon his return from Atlanta in 1968. Unfortunately, his assassination in Memphis on April 4th, 1968 prevented that from happening.

Explanation:

d) a constitutional amendment

which time period is this? or is this story fictional, i'm going to need more info to answer this question