The Anti-Federalists were never a political party as is thought of in modern times. It was a coalesced group of voting interests that were united in their opposition to the Constitution.

"The Antifederal objections to the Constitution fall into four categories. First, some attacked it for violations of the Whig theory. Such criticisms came particularly from merchants, lawyers and large landowners who believed in Whig ideology themselves, and represented a sort of right wing, non-agrarian Antifederalism. Second, almost all of the new plan's opponents accused it of excessive centralization: these were the localists. Third, some critics attacked the Constitution as leading toward monarchy or aristocracy rather than democracy: these comprised the left wing. Finally, the agrarians feared that the commerical, creditor, or large propertied interests would benefit at the expense of the farmers." (Jackson T. Main, History of U.S. Political Parties Volume I: 1789-1860: From Factions to Parties. Arthur M. Schlesinger, Jr., ed. New York, 1973, Chelsea House Publisher. p. 153.)

"Strictly speaking, Antifederalism ended with the ratification of the Constitution in 1788, without ever producing a party in any modern sense. During the next few years the term continued as a word of opprobrium, employed by the Federalists to demean whoever opposed the men or policies of the new government. In some states, opposition nearly ceased. In others, however, former Antifederalists remained strong and even gained ground, especially where they had developed a local political organization: they composed a majority or a strong minority in such states as New Hampshire, Massachusetts, Rhode Island, New York, Pennsylvania, Virginia, and North Carolina, and appeared elsewhere for the first time, as in New Jersey. Although they still lacked an inter-state organization and suffered a serious loss of strength during the election of 1788-1789, bitterly fought in certain areas. Presently, in Congress, they supported amendments and opposed various policies of the Federalists. The close relationship between the Anti-Federalists and the Jeffersonian Republicans may be traced through a continuity both of men and ideas. At least seven-eighths of those known to have opposed the Constitution in 1787-1788 became Republicans." (Main, p. 166)

"Despite the intensity of Anti-Federalist opposition to the Constitution, no Anti-Constitution party emerged after ratification. With the demise of the second-convention movement, Anti-Federalists turned their attention to seeking office under the new government. Federalist efforts to discredit Anti-Federalists turned their attention to seeking office under the new government. Federalist efforts to discredit Anti-Federalists only diminshed the likelihood of a distinctive Anti-Federalist party's emerging. Instead, Anti-Federalists set about becoming a loyal opposition. A number of other factors facilitated this transformation. The rapid adoption of the Bill of Rights, even if it failed to satisfy many Anti-Federalists, deprived them of an important rallying point. Reverence for the principles of constitutionalism and a belief that, when properly amended, the new frame of government would effectively protect liberty further weakened the chances of an Anti-Federal's party forming. The respect accorded George Washington, the new president, also worked against continued opposition. When coupled with renewed econimic prosperity, all of those factors helped promote the formal demise of Anti-Federalism. Yet, though Anti-Federalism did not generate an Anti-Constitution party, the term 'Anti-Federalist,' the various texts produced by the Anti-Federalists during ratification, and the alternative constitutional discourses that shaped Anti-Federalism did not simply disappear. The emergence of a court faction among Federalists caused many former supporters of the Constitution to rehtink the original Anti-Federalist critique. The efforts of former Federalists, most notable James Madison, and former Anti-Federalists, such as William Findley, were crucial to the creation of a Democratic-Republican opposition. That loyal opposition drew important ideas and rhetorical themes from Anti-Federalism and adapted them to the exigencies of political conflict in the 1790s." (p. 170-171)

Additional Sources:

• History of U.S. Political Parties Volume I: 1789-1860: From Factions to Parties. Arthur M. Schlesinger, Jr., ed. New York, 1973, Chelsea House Publisher.
• The Other Founders: Anti-Federalism and the Dissenting Tradition in America, 1788-1828. Saul Cornell. Chapel Hill, 1999, University of North Carolina Press.