In the early 1980s, the majority of cocaine being shipped to the United States, landing in Miami, was coming through the Bahamas and Dominican Republic. Soon there was a huge glut of cocaine powder in these islands, which caused the price to drop by as much as 80 percent. Faced with dropping prices for their illegal product, drug dealers made a decision to convert the powder to "crack," a solid smoke able form of cocaine, that could be sold in smaller quantities, to more people. It was cheap, simple to produce, ready to use, and highly profitable for dealers to develop. As early as 1981, reports of crack were appearing in Los Angeles, Oakland, San Diego, Miami, Houston, and in the Caribbean.
This was most likely in the song because all american where on crack at the time because it just came out.