As the federal government is one of enumerated powers rather than of general powers, we find the power to levy taxes expressly conferred upon Congress in the federal constitution. Perhaps the power to levy taxes for the purpose of carrying out the objects for which the federal government was created would have been necessarily implied without specific provision; but one of the difficulties attending the form of government provided for by the Articles of Confederation was that it could not exercise the power of taxing persons or property, but was dependent on contributions from the state governments; and while the Congress of the Confederation could apportion among the states the charges of war and of other expenses incurred for the common defence and welfare, no method was provided by which the states could be compelled to raise and turn over to the federal government the sums thus apportioned to them. It was to be expected, therefore, that the framers of the federal constitution should incorporate therein some specific provision by which the federal government should have this power so essential to its existence. This specific authority is given in the following clause: "The Congress shall have power: - To lay and collect taxes, duties, imposts and excises, to pay the debts and provide for the common defense and general welfare of the United States; but all duties, imposts, and excises shall be uniform throughout the United States" (Art. I, § 8, ¶ 1). The power to tax for the purpose of raising public money is thus specifically given, and the purposes for which taxes may be levied and collected are as broad as the needs of the government can possibly be, for any public purpose within the scope of the powers given to the federal government would fall within the authority to raise revenue, "To pay the debts and provide for the common defense and general welfare." Within this general authority, it is for Congress to determine what is a proper purpose and the method and extent of exercising the taxing power. The power to tax thus given to Congress undoubtedly extends in a general way to all persons and property within the jurisdiction of the United States. But the further specification of the power to lay and collect duties, imposts, and excises, with the concluding limitation that they shall be uniform throughout the United States, suggests a distinction between such duties, imposts, and excises which are required to be uniform, and direct taxes which, by other provisions, are required to be apportioned among the several states according to population (Art. I, § 2, ¶ 3, and § 9, ¶ 4). These two forms of federal taxation will therefore be separately considered.