Book excerpt: For 100 years, the Congressional Research Service (CRS) has been charged with providing nonpartisan and authoritative research and analysis to inform the legislative debate in Congress. This has involved a wide range of services, such as written reports on issues and the legislative process, consultations with Members and their staff, seminars on policy and procedural matters, and congressional testimony. The Government and Finance Division at CRS took a step back from its intensive day-to-day service to Congress to analyze important trends in the evolution of the institution-its organization and policymaking process-over the last many decades. Changes in the political landscape, technology, and representational norms have required Congress to evolve as the Nation's most democratic national institution of governance. The essays in this print demonstrate that Congress has been a flexible institution that has changed markedly in recent years in response to the social and political environment.