Congress is overwhelmed. It has become so overwhelmed its constitutional status as a co-equal branch of government is at serious risk. In this volume, leading congressional scholars explore the causes and consequences of Congress’s decades-long neglect in itself. The first branch of government no longer has the capacity to govern as it once did. The volume explores the state of congressional capacity, or the human capital and other resources that Congress has available to perform its role in resolving public problems by legislating, budgeting, holding hearings, conducting oversight, and serving constituents. In so doing, it offers a new perspective to existing scholarship, which focuses only on partisan polarization as the source for legislative dysfunction. The chapters assess Congress’s declining capacity using a variety of analytic approaches and data sources. Several contributions report the first findings from the 2017 Congressional Capacity Survey, the largest and most comprehensive mixed-method study of congressional staff ever conducted. Some chapters investigate Congress’s political development to illuminate how capacity has changed throughout history in response to broader political forces. Others evaluate how Congress manages its legislative workload despite heightened polarization and the perpetual campaign. And, several scholars explore how Congress could reform itself. Taken together, the volume offers new ways for thinking about congressional capacity, and ample evidence to show that Congress is approaching, if it has not already reached, the nadir of its ability to solve problems on behalf of the American people.