In 1954, psychiatrist Fredric Wertham published Seduction of the Innocent, in which he criticized comic books as damaging to youth and warned how they would increase juvenile delinquency.
At the time, there were already growing tensions and concerns about comic books and their influence on adolescents and juvenile delinquency. Parents became alarmed and the book drew attention from the media and the government.
In an effort to allow comic publishers to self-regulate, the U.S. comic book industry established the Comics Magazine Association of America which later instituted the Comics Code Authority, an alternative to government regulation.
This history may be found in the sources below. Additionally, a catalog search under the subject heading "Comic books, strips, etc. -- Moral and ethical aspects", will provide further results.