Crack cocaine is the freebase form of cocaine that can be smoked. It may also be termed rock, hard, iron, cavvy, base, or just crack; it is the most addictive form of cocaine. Crack rocks offer a short but intense high to smokers. Crack appeared primarily in impoverished inner-city neighborhoods in New York, Los Angeles, and Miami in late 1984 and 1985. Its rise to popularity can be attributed to the discovery that baking soda (sodium bicarbonate, NaHCO₃) was a low-cost and simple replacement for the diethyl ether used in preparation of free base cocaine. The name "crack" refers to the sound generated during its manufacture and when smoked.

In purer forms, crack rocks appear as off-white nuggets with jagged edges, with a slightly higher density than candle wax. Purer forms of crack resemble a hard brittle plastic, in crystalline form (snaps when broken). A crack rock acts as a local anesthetic (see: cocaine), numbing the tongue or mouth only where directly placed. When smoked, crack can leave the tongue numb where the smoke enters the mouth.^{[citation needed]} Purer forms of crack will sink in water or melt at the edges when near a flame (crack vaporizes at 90 °C, 194 °F).

Cypress Hill is an American hip hop group from South Gate, California. Cypress Hill was the first Cuban-American/Latino hip hop group to have platinum and multi-platinum albums, selling over 18 million albums worldwide. It is one of the most well-known groups in West Coast rap and was critically acclaimed for their first two groundbreaking albums.

Senen Reyes (also known as Sen Dog) and Ulpiano Sergio Reyes (also known as Mellow Man Ace) are brothers who initially lived in South Gate, California. In 1971, their family had immigrated to the United States, settling in the Los Angeles neighborhood of South Gate. In 1988, the two brothers teamed up with Lawrence Muggerud (also known as DJ Muggs) and Louis Freese (also known as B-Real) to form a hip-hop group named DVX (Devastating Vocal Excellence). The band soon lost Mellow Man Ace to a solo career, and changed their name to Cypress Hill, after a street in South Gate.

After recording a demo in 1989, Cypress Hill signed a record deal with the major label, Columbia Records. Their self-titled first album was released in August 1991. The lead single was the double A-side "The Phuncky Feel One"/"How I Could Just Kill a Man" which received heavy airplay on urban and college radio. The other two singles released from the album were "Hand on the Pump" and "Latin Lingo", the latter of which combined English and Spanish lyrics. The success of these singles led to the album selling two million copies in the US alone. The group made their first appearance at Lollapalooza on the side stage in 1992.