Abstract: Congressional policymaking occurs in an information-rich environment, among a vast and complex set of institutional and representational demands. In this dissertation, I examine how congressional institutions interact with the broader political and policymaking environment in order to successfully manipulate the policy process. My theory of information management in Congress argues that committees and subcommittees provide the Congress with the management tools necessary to adaptively respond to demands in the policy environment by structuring the flow of information in policy debates and facilitate policymaking success, primarily through the use of congressional hearings. Using expectations produced by my theory of information management in Congress, I address four primary research questions: (1) When and why do committees publicly manage information? (2) When and why do committees delegate the management of information to subcommittees? (3) Which subcommittees are most likely to conduct information management activities and why? (4) How do committees utilize subcommittees in the management of information to generate policy success? Utilizing my theory of information management in Congress, I derive empirically testable hypothesis regarding the influences on and impact of committee and subcommittee hearing activity in the U.S. Congress. I assemble original datasets of committee and subcommittee characteristics and hearing activity in both the House and Senate via a variety of primary and secondary sources. I supplement my theoretical developments and quantitative analyses of committee and subcommittee activity and success with qualitative data collected via semi-structured interviews with House and Senate committee staff, and participant observations made by the author while working for the House Committee on Education and Labor during the first session of the 111th Congress. Statistical analyses and illustrative anecdotes provide consistent empirical evidence supporting my expectations for committee and subcommittee activity and influence. I find that Congress’ committee system is able to respond to simultaneous and competing demands facing the national policy making process. Through adaptively managing the flow of information in the policy debate, committees and subcommittees provide Congress with the tools required to navigate the complex policy environment to achieve policy success. Additionally I find that while House and Senate committees appear to serve a common purpose and generate similar influence in the policy process, despite variation in the details of how certain factors in the policy environment influence committee and subcommittee activity and success across chambers. By presenting and examining a generalizable explanation of legislative organization in both the House and Senate, as well as revealing the influential role of subcommittees in the policy process, this dissertation makes unique contributions to the study policymaking in congressional institutions.