The Congress of the United States operates in the shadow of the American presidency, which can make the legislative branch appear less important than the executive in our constitutional system of government. And yet Congress is a co-equal branch of government, deriving its powers from Article I of the United States Constitution. Love it or hate it, the institution is a source of incredible power. It behooves all Americans to learn more about Congress. Although a single slender volume cannot provide information on all there is to know about Congress, it can begin the journey. In Congressional Giants, political scientist J. Michael Martinez explores the careers and achievements of 14 influential leaders of Congress—men who either held formal positions within the chambers of Congress, such as speaker of the House of Representatives or Senate majority leader, or who served on important committees—to determine how they shaped the course of American history.