The Articles of Confederation had created a Congress with very circumscribed and carefully enumerated powers. Throughout much of the Convention, the delegates had toyed with the idea of granting to the new legislature very broad, unspecified powers. The Virginia Plan had empowered Congress: “To legislate in all cases, to which the separate States are incompetent, or in which the harmony of the United States may be interrupted by the exercise of individual legislation.” That broad grant of powers came to an end when the Committee of Detail created a separate article enumerating the powers of the new Congress.
The list of congressional powers in the Articles of Confederation is in fact quite long, and the corresponding list in the Constitution is considerably shorter. The main reason for this difference is the same as the one accounting for the differences in the prohibitions of state powers: The Articles had tried to specify numerous exceptions, qualifications, and complications in their list of powers. Although the enumeration of powers in the Constitution takes up far less space, it includes far more powers. Some of these new powers were formidable—such as laying taxes, regulating commerce, raising armies, and making “all Laws which shall be necessary and proper for carrying into Execution the foregoing Powers”—and some Antifederalists expressed horror at the extent of the new enumeration. Within the Convention, however, the specific powers of Congress provoked surprisingly little disagreement or debate.
It is worth noting that in some respects the new Congress would have fewer powers than the old one. In each case, this was the result of dividing the federal powers into three separate branches of government. Some of the powers that had formerly been exercised by the Confederation Congress were now to be exercised by the judiciary branch (such as settling disputes between the states), by the executive branch (such as commissioning officers of the United States and directing military operations), or shared between the Senate and the president (such as the appointment and treaty-making powers). The Constitution did not shift any of the powers listed in the Articles from the federal government to the states, but it did shift powers from the federal legislature to other branches within the new federal government.