The racist associations between crack and black people are rumored to actually be an intentional thing. The US government says the allegations have no merit, but the CIA has been accused of funneling large amounts of crack cocaine into the black neighborhoods of LA. Here's one article about it on a .gov but you can find many other sources on google: THE CIA-CONTRA-CRACK COCAINE CONTROVERSY Relevant quote from the original source accusing them:

For the better part of a decade, a San Francisco Bay Area drug ring sold tons of cocaine to the Crips and Bloods street gangs of Los Angeles and funneled millions in drug profits to a Latin American guerrilla army run by the U.S. Central Intelligence Agency, a Mercury News investigation has found.

This drug network opened the first pipeline between Colombia's cocaine cartels and the black neighborhoods of Los Angeles, a city now known as the "crack" capital of the world. The cocaine that flooded in helped spark a crack explosion in urban America . . . and provided the cash and connections needed for L.A.'s gangs to buy automatic weapons.