the Founding Fathers
It is likely that many of the Founding Fathers of the United States were at least partially Calvinist in their theological beliefs. The Pilgrims and the Puritans - two important early groups of settlers - were Calvinists. The Reformed, Presbyterian and Congregationalist churches -- all of which were significant Colonial denominations at the time of the American Revolution - were Calvinist.
Despite the prevalence of Calvinism among Colonials, most most Founding Fathers were apparently not identified primarily by the label "Calvinist." Among all of the people who were signers of the Declaration of Independence, signers of the U.S. Constitution, and members of the very first U.S. Congress and Senate, there is only one man whose religious affiliation is identified as "Calvinist": Fisher Ames.
(Virtually all of these signers and original congressmen and senators were Christians, but all others were identified as members of specific denominations, such as Episcopalian, Presbyterian, Congregationalist, etc.)
Name: Fisher Ames
Religious affiliation: Calvinist
Another Founding Father who was certainly a Calvinist was William Livingston, a delegate from New Jersey to the Constitutional Convention and a signer of the U.S. Constitution. William Livingston was a Presbyterian, but he strongly identified with Calvinism and an important part of his career involved his representing Calvinist causes (often in opposition to Anglicans) in New Jersey politics.
How many of the other Founding Fathers could probably be classified as Calvinists, based on their denominational affiliation? A lot. Of the 165 different men who were signers of Declaration of Independence, signers of the U.S. Constitution, or who were Senators or Representatives in the First Federal Congress, 21 were Congregationalists (13%), 20 were Presbyterians (12%), 5 were Dutch Reformed or German Reformed (3%) and 1 was a Huguenot. If these individuals whose denominations were officially Calvinist are added to Fisher Ames, then one can count at least 48 (29%) of the Founding Fathers as Calvinists.
It was not until the 1800s that Calvinism began to be more fully expunged from Christian thought in America. Numerous influential American religious founders and theologians soundly rejected Calvinism, including Barton W. Stone, John Mulkey, Alexander Campbell, Joseph Smith Jr., Walter Scott, Sydney Rigdon, James Relly, and Neal Punt. Today Calvinism remains an influential part of many Protestant denominations, but its significance has waned. Most Americans of all denominations are solidly non-Calvinist in their religious beliefs and general outlook.
Sources: "Representatives Elected to the United States Congress: The 1st Federal Congress of the United States of America (1789-1791)" in "Religion in the United States Government" section of "World Information" website (http://www.bizforum.org/FFR-Congress.htm); "Signers of the Declaration of Independence - July 4th, 1776" in "Religion in the United States Government" section of "World Information" website (http://www.bizforum.org/FFR-DoI.htm); "Signers of the Constitution of the United States of America" in "Religion in the United States Government" section of "World Information" website (http://www.bizforum.org/FFR.htm); "Senators Elected to the United States Senate: The 1st Federal Congress of the United States of America (1789-1791)" in "Religion in the United States Government" section of "World Information" website (http://www.bizforum.org/FFR-Senate.htm); viewed 8 July 2005