"High levels of drug use and experimentation in the 1960s resulted in numerous long prison sentences under the Boggs Act.31 In 1970, Congress responded to the concerns of prosecutors, wardens, and families of those convicted, repealing virtually all provisions imposing mandatory minimum sentences for drug violations.32 Congress commented that lengthening prison sentences 'had not shown the expected overall reduction in drug law violations.'33"
Source
Mascharka, Christopher, "Mandatory Minimum Sentences: Exemplifying the Law of Unintended Consequences," Florida State University Law Review (Tallahassee, FL: Florida State University, Summer 2001) Volume 28, Number 4, p. 939.
http://www.law.fsu.edu/journa…
