The 'Humanist Manifesto I' was signed by the following people:
J.A.C. Fagginger Auer—Parkman Professor of Church History and Theology, Harvard University; Professor of Church History, Tufts College.
E. Burdette Backus—Unitarian Minister.
Harry Elmer Barnes—General Editorial Department, ScrippsHoward Newspapers.
L.M. Birkhead—The Liberal Center, Kansas City, Missouri.
Raymond B. Bragg—Secretary, Western Unitarian Conference.
Edwin Arthur Burtt—Professor of Philosophy, Sage School of Philosophy, Cornell University.
Ernest Caldecott—Minister, First Unitarian Church, Los Angeles, California.
A.J. Carlson—Professor of Physiology, University of Chicago.
John Dewey—Columbia University.
Albert C. Dieffenbach—Formerly Editor of The Christian Register.
John H. Dietrich—Minister, First Unitarian Society, Minneapolis.
Bernard Fantus—Professor of Therapeutics, College of Medicine, University of Illinois.
William Floyd—Editor of The Arbitrator, New York City.
F.H. Hankins—Professor of Economics and Sociology, Smith College.
A. Eustace Haydon—Professor of History of Religions, University of Chicago.
Llewellyn Jones—Literary critic and author.
Robert Morss Lovett—Editor, The New Republic; Professor of English, University of Chicago.
Harold P Marley—Minister, The Fellowship of Liberal Religion, Ann Arbor, Michigan.
R. Lester Mondale—Minister, Unitarian Church, Evanston, Illinois.
Charles Francis Potter—Leader and Founder, the First Humanist Society of New York, Inc.
John Herman Randall, Jr.—Department of Philosophy, Columbia University.
Curtis W. Reese—Dean, Abraham Lincoln Center, Chicago.
Oliver L. Reiser—Associate Professor of Philosophy, University of Pittsburgh.
Roy Wood Sellars—Professor of Philosophy, University of Michigan.
Clinton Lee Scott—Minister, Universalist Church, Peoria, Illinois.
Maynard Shipley—President, The Science League of America.
W. Frank Swift—Director, Boston Ethical Society.
V.T. Thayer—Educational Director, Ethical Culture Schools.
Eldred C. Vanderlaan—Leader of the Free Fellowship, Berkeley, California.
Joseph Walker—Attorney, Boston, Massachusetts.
Jacob J. Weinstein—Rabbi; Advisor to Jewish Students, Columbia University.
Frank S.C. Wicks—All Souls Unitarian Church, Indianapolis.
David Rhys Williams—Minister, Unitarian Church, Rochester, New York.
Edwin H. Wilson—Managing Editor, The New Humanist, Chicago, Illinois; Minister, Third Unitarian Church, Chicago, Illinois.