This chapter starts by reviewing the history of American news media since 1789, focusing on how new production technologies and business models led to a comparatively unbiased, objective journalism in the mid-20th Century. The difference today that audiences have become far more polarized. This has enabled market segmentation strategies in which each broadcaster avoid competition by pandering to a different political viewpoint. More recently, the rise of the Web has accelerated the rate at which new political messages can be invented, tested on audiences, and eventually refined to the point where mainstream outlets are prepared to broadcast it. The question remains how effectively large news organizations and Web platforms can suppress information they disagree with. The chapter explores when and to what extent todays markets permit this.