War Taxes.—­Because taxes of this kind are so easily collected, the government has extended them to a great number of articles when it suddenly needed a large revenue, as in the War of 1812, the Civil War, and the Spanish War of 1898.  The law of 1898 increased the taxes on liquors and tobacco, and imposed new taxes on (1) proprietary articles, and (2) documents.  Under the first heading fall patent medicines and compounds of various kinds.  Documentary taxes[24] were imposed upon legal papers, such as deeds, mortgages, etc., and also upon bank checks and drafts, telegraph and telephone messages, and express receipts.  Under this law the internal revenue receipts rose from $170,000,000 in 1898, to $273,000,000 in 1899.  Congress has repealed these special war taxes.

     [Footnote 24:  These were exactly like those imposed by Parliament
     in the Stamp Act of 1765.]

Corporation Tax.—­In 1909 Congress levied a tax upon corporations.  Every corporation doing interstate business is required to report its earnings and its expenses.  The difference between these amounts is its net earnings.  The law requires the payment of one per cent of the net earnings that are in excess of $5000.

Rules for Levying Taxes.—­The Constitution contains three rules by which Congress must be guided in the levying of taxes.  We have seen, Article I, Section 8, Clause 1, that duties, imposts and excises must be uniform throughout the United States; that is, the same rates must prevail everywhere.  Another provision, Article I, Section 2, Clause 3, is that representatives and direct taxes shall be apportioned among the several States ... according to their respective numbers.[25]

[Footnote 25:  See also Article 1, Section 9, Clause 4:  No capitation, or other direct, tax shall be laid unless in proportion to the census or enumeration hereinbefore directed to be taken.]

The third provision is the Sixteenth Amendment, which became a part of the Constitution in February, 1913:  Article 16. The Congress shall have power to lay and collect taxes on incomes, from whatever source derived, without apportionment among the several States, and without regard to any census or enumeration.

We have, therefore, the following classification:—­

I. Direct | persons,[26]| Must be apportioned among
   taxes, | lands, | the States according to
   levied on | | population.

II.  Indirect | duties, | Must be uniform throughout
    taxes | imposts, | the United States.
             | excises, |
             | income |
             | taxes. |

[Footnote 26:  These are poll taxes.  Such a tax was levied on slaves in 1798 and 1813.]

So far, we have discussed the indirect taxes only, for at present the United States levies no direct taxes.  In our previous history, however, the government has imposed all the kinds of taxes mentioned in the outline above.  In levying a direct tax, Congress must determine the total amount to be raised (as $2,000,000 in 1798, and $20,000,000 in 1861), and then apportion this amount among the States, according to their population.