Nathaniel Gorham was a Congregationalist.
He was identified as a Congregationalist by: the Library of Congress and A Worthy Company: Brief Lives of the Framers of the United States Constitution, written by M. E. Bradford. (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), page 172:
Gorham died in 1796 at the age of 58 and is buried at the Phipps Street Cemetery in Charlestown, Mass.
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.