Article 1, Section 2, Clause 3

Representatives and direct Taxes shall be apportioned among the several States which may be included within this Union, according to their respective Numbers, which shall be determined by adding to the whole Number of free Persons, including those bound to Service for a Term of Years, and excluding Indians not taxed, three fifths of all other Persons. The actual Enumeration shall be made within three Years after the first Meeting of the Congress of the United States, and within every subsequent Term of ten Years, in such Manner as they shall by Law direct. The Number of Representatives shall not exceed one for every thirty Thousand, but each State shall have at Least one Representative; and until such enumeration shall be made, the State of New Hampshire shall be entitled to chuse three, Massachusetts eight, Rhode-Island and Providence Plantations one, Connecticut five, New-York six, New Jersey four, Pennsylvania eight, Delaware one, Maryland six, Virginia ten, North Carolina five, South Carolina five, and Georgia three.

1.Continental Congress, Taxation and Representation, 12 July 1776
2.Records of the Federal Convention
3.Letter from a Gentleman from Massachusetts, 17 Oct. 1787
4.A Federal Republican, Review of the Constitution Proposed by the Late Convention, 28 Oct. 1787
5.Brutus, no. 3, 15 Nov. 1787
6.Cato, no. 5, Fall 1787
7.James Wilson, Pennsylvania Ratifying Convention, 30 Nov. 4 Dec. 1787
8.The Address and Reasons of Dissent of the Minority of the Convention of Pennsylvania to Their Constituents, 18 Dec. 1787
9.Luther Martin, Genuine Information, 1788
10.Alexander Hamilton, Federalist, no. 36, 226, 229--30, 8 Jan. 1788
11.Debate in Massachusetts Ratifying Convention, 17--19 Jan. 1788
12.A Republican Federalist, no. 5, 19 Jan. 1788
13.James Madison, Federalist, no. 54, 366--72, 12 Feb. 1788
14.James Madison, Federalist, no. 55, 372--78, 13 Feb. 1788
15.James Madison, Federalist, no. 56, 378--83, 16 Feb. 1788
16.James Madison, Federalist, no. 57, 384--90, 19 Feb. 1788
17.James Madison, Federalist, no. 58, 391--97, 20 Feb. 1788
18.Debate in Virginia Ratifying Convention, 4--5 June 1788
19.James Madison, Census Bill, House of Representatives, 25--26 Jan. 2 Feb. 1790
20.Hylton v. United States
21.St. George Tucker, Blackstone's Commentaries 1:App. 189, 1803
22.Joseph Story, Commentaries on the Constitution 2:§§ 630--35, 641--47, 673--80, 1833