What is the history behind cigarette warning labels?

In 1966 the Federal government mandated that cigarette packs have a warning on them from the surgeon general. See Tobacco packaging warning messages. Congress voted in 1973 that products containing toxic substances must have labels. In 1985 there was a testimony that wanted record companies to put labels on music that contained sexual or violent lyrics. On March 29, 1990 warning labels were put on music products that contained potentially offensive lyrics; this was done with the agreement of the recording companies. In 1989, alcohol was required to have their surgeon generals warning.