Herbert Hoover was a Quaker.
From: Peter Roberts, "Herbert Clark Hoover" page in "God and Country" section of "Science Resources on the Net" website (http://www.geocities.com/peterroberts.geo/Relig-Politics/HCHoover.html; viewed 29 November 2005):
Religious Affiliation: (Society of Friends) Quaker
"For centuries, the human race believed that divine inspiration rested in a few. The result was blind faith in religious hierarchies, the Divine Right of Kings. The world has been disillusioned of this belief that divinity rests in any special group or class whether it be through a creed, a tyranny of kinds or of proletariat. Our individualism insists upon the divine in each human being. It rests upon the divine in each human being. It rests upon the firm faith that the divine spark can be awakened in every heart. It was the refusal to compromise these things that led to the migration of those religious groups who so largely composed our forefathers. Our diversified religious faiths are the apotheosis of spiritual individualism." -- American Individualism, 1922
"I come of Quaker stock. My ancestors were persecuted for their beliefs. Here they sought and found religious freedom. By blood and conviction I stand for religious tolerance both in act and in spirit." -- New Day, 1928
"The migration of our forefathers to America was in refuge from the continued regimentation of men and men's minds still frozen by classes, by feudalism, by the churches, and by governments. Liberty was already implicit in their religious beliefs and their spiritual aspirations. Their purpose was to establish it in government." -- The Challenge to Liberty, 1934, p18