William Samuel Johnson was also a U.S. Senator in the First U.S. Federal Congress (1789-1791).
William Samuel Johnson was a Presbyterian and an Episcopalian.
He was identified as a Presbyterian by the 1995 Information Please Almanac. the Library of Congress and A Worthy Company: Brief Lives of the Framers of the United States Constitution, written by M. E. Bradford were cited as the sources stating he was later an Episcopalian. (Source: Ian Dorion, "Table of the Religious Affiliations of American Founders", 1997).
From: Robert G. Ferris (editor), Signers of the Constitution: Historic Places Commemorating the Signing of the Constitution, published by the United States Department of the Interior, National Park Service: Washington, D.C. (revised edition 1976), pages 1748-180:
Scholar, lawyer-jurist, and politician, Johnson was one of the best educated of the signers [of the U.S. Constitution]... The son of Samuel Johnson, the first president of King's College (later Columbia College and University), William was born at Stratford, Conn., in 1727. His father, who was a well-known Anglican clergyman-philosopher, prepared him for college and he graduated from Yale in 1744. About 3 years later, he won a master of arts degree from the same institution and an honorary masters from Harvard.
Resisting his father's wish that he become a minister, Johnson embraced law instead...
At the time of the Revolution, conflicting loyalties disturbed Johnson... Many of his friends resided in Britain; in 1765 and 1766 Oxford University conferred honorary masters and doctors degrees upon him; he had a strong association with the Anglican Church; he acted as Connecticut's agent in Britain during the years 1767-71...
...In 1791... he resigned [as a U.S. Sentor] mainly because he preferred to devote all his energies to the presidency of Columbia College (1787-1800), in New York City... He died [in Stratford] in 1819 and was buried at Old Episcopal Cemetery.
Note that numerous sources and authoritative references have been consulted in order to ascertain the religious affiliation of the American Founding Fathers. Note that the excerpts and references mentioned on this page are not the only references used in order to identify this person's religious affiliation.