1961, "comedy that deals in themes and subjects usually regarded as serious or taboo," from black (adj.), in a figurative sense of "morbid," + comedy. Compare French pièce noire, also comédie noire "macabre or farcical rendering of a violent or tragic theme" (1958, perhaps the inspiration for the English term) and 19th-century gallows-humor. In a racial sense, from 1921.
"right of each citizen to liberty, equality, etc.," 1721, American English, from civil in the sense "pertaining to the citizen in his relations to the organized commonwealth or to his fellow citizens." Specifically of black U.S. citizens from 1866, in reference to the Civil Rights Bill, an act of Congress which conferred citizenship upon all persons born in the United States, not subjects of other powers, "of every race and color, without regard to any previous condition of slavery." Civil Rights Movement in reference to the drive for racial equality that began in U.S. in mid-1950s is attested by 1963.
Rarely are we met with a challenge, not to our growth or abundance, or our welfare or our security, but rather to the values and the purposes and the meaning of our beloved nation. The issue of equal rights for American Negroes is such an issue. And should we defeat every enemy, and should we double our wealth and conquer the stars, and still be unequal to this issue, then we will have failed as a people and as a nation. [Lyndon Johnson, speech introducing Voting Rights Act, March 15, 1965]