The national legislature created by the Articles of Confederation lacked sufficient powers to govern the country properly. The Constitutional Convention of 1787 created a stronger Congress with adequate powers to govern. The legislative powers were enumerated, or listed, in Article I, Section 8, whereas Article I, Section 9 enumerated powers which Congress was constitutionally restricted from exercising. Article VI made constitutional congressional laws and treaties part of the supreme law of the land. During the 1787-1788 ratification debate over the Constitution, the Federalists defended the strengthened, though limited, legislative branch and its relationship to the executive and judicial branches. The Anti-Federalists were critics of the Constitution including the Congress because they argued that it had unlimited powers and would destroy liberty.

During the first century of the United States, the Congress acted upon the powers delegated to it by the Constitution, particularly those enumerated in Article I, Section 8. While this entailed some regulation by the national government, most economic policies were enacted at the state and local levels, and the federal government exercised little regulation of the economy. In the decades that followed the Civil War, the scope of power of Congress would grow exponentially. This expansion of power was fueled by new interpretations of the Commerce Clause in Article I, Section 8, which empowered Congress to “regulate interstate commerce.” However in the late nineteenth and twentieth centuries it was interpreted to justify a regulatory state that encompassed almost every aspect of American public life. These interpretations were confirmed and expanded by a series of Supreme Court decisions. The Supreme Court allowed Congress to exercise new powers in the name of commerce and to delegate its regulatory authority to the executive. In recent years there has been more resistance to this course of expansion. The Supreme Court more narrowly defined what commerce is and restricted the scope of congressional power. This has been further advanced by rules changes in the House of Representatives that require new bills to be more closely aligned with the enumerated powers of the Constitution.