If this is a paper for a university I would suggest looking up scholarly articles related to censorship of the Media via JSTOR or some other research port provided by your library. you might want to also look up some credible story of an instance when the media was caught censoring its story. Have you developed a thesis yet because censorship in America seems a little ambiguous....I mean are you trying to prove that media censorship in America exists or are you trying to discuss the consequences of media censorship in America?