PCP was created after World War II as a surgical anesthetic. It worked well, but there were serious side effects: hallucinations, jumbled speech, and delirium. Around the mid-to-late 1960s, the drug sprang up on the streets of San Francisco as a "Peace Pill." People soon realized that it was a very dangerous drug. In the San Francisco area, the use of PCP died out before the 1970s. At the same time, the drug was becoming more common in New York, and it spread quickly there. However, its use in this area died out, like in San Francisco. The United States made it illegal to use PCP for any reason, or to make the drug, because of its serious effects.