This paper explores IBM's relationship with its competitors during the period it became a truly major corporation. More specifically, the paper focuses on how IBM managed to outperform its competitors from 1933 to 1970, and thereby become the dominant firm in the business machines sector of the American economy. At the center of the story are IBM's unusually close relationships with the leaders of the federal government during that era. Those relationships helped IBM win very big government contracts and also appear to have deterred very aggressive antitrust action against it. That combination helped IBM overtake its competitiors.