Congressional scholars regularly identify Speaker Joseph G. Cannon as the personification of centralized authority and partisan strength in the United States Congress. Portraits of Cannon as a tyrant, however, are almost always based on anecdotal evidence and journalistic accounts. This paper assesses the conventional wisdom on Cannonism by systematically analyzing committee transfer patterns. Anecdotal evidence is consistent with recent theories of parties in legislatures, suggesting that Cannon employed seemingly unilateral committee assignment powers to punish occasional defectors on key votes of the Republican agenda and, thereby, to maintain partisan discipline. Employing the Groseclose-Stewart (1998) method for estimating values of committee seats, we study variation in member-specific committee portfolio values. The data are useful not only for reassessing the historical thesis of Cannon as tyrant, but also for testing more recent political-science hypotheses about the underpinnings of a strong majority party. The findings fail to corroborate the notions of majority-party power and Cannon as tyrant. If anything, systematic data supports a new portrait of Cannon as a majoritarian.