What does Congress do? How does it do it? Why is it such a complicated institution? This concise primer offers students and general readers a brief and systematic introduction to Congress and the role it plays in the US political system. Drawing on his experience as a former Congressional staff member, the author explores the different political natures of the House and Senate, examines Congress's interaction with other branches of the Federal government, and looks ahead to the domestic and foreign challenges that are likely to drive the Congressional agenda for decades to come. The book provides revealing insights into the sometimes-contradictory Congressional responsibilities of representation and lawmaking; oversight and appropriation; and managing and organizing the government. It includes a case study (on the formation of the Department of Homeland Security) that sheds light on Congress's often-complicated procedures. The book also includes boxed features on Congressional action - highlighting such topics as file sharing and student loans - that show students how Congress's work affects their lives. Chapter-ending lists of web resources add to the book's usefulness.