Professor Brought Christmas Tree to New England
From the Harvard Gazette, an article on Unitarian minister and abolitionist Charles Follen, and the story of how he promoted the Christmas tree.
http://www.news.harvard.edu/gazette/1996/12.12/ProfessorBrough.html

Unitarian Universalists in Science Fiction
Annotated list of science fiction novels and stories with UU characters or references. Also, UU authors of science fiction.
http://www.adherents.com/lit/sf_uu.html

Universalism on the Pacific Coast
Articles include history of individual churches, including ones that no longer exist.
http://www.lafn.org/~dave/uu/universalism

Socinianism
Catholic Encyclopedia article on this body of doctrine held by one of the Antitrinitarian sects that gave rise to Unitarianism.
http://www.newadvent.org/cathen/14113a.htm

Unitarian Universalist Origins
History of the Unitarian Universalist religion by Mark W. Harris, former director of public information for the UUA.
http://www.uua.org/info/origins.html

Reflections of Public Ministry at Harvard Divinity School
An online exhibit.
http://www.hds.harvard.edu/library/exhibits/online/hdspublicministry/

Unitarian History
An article written by Ken Morrison of the Lakehead Unitarian Fellowship, Thunder Bay, Ontario, Canada.
http://www.luf.ca/uuhist.htm

Dictionary of Unitarian and Universalist Biography
Online biographies commissioned by the Unitarian Universalist Historical Society.
http://www.uua.org/uuhs/duub/

The Unitarian Universalist Tradition: A Basic Research and Reading List
Annotated list of print and Internet resources, prepared for the Harvard Divinity School community by Andover-Harvard Theological Library.
http://www.hds.harvard.edu/library/research/guides/uu/index.html

Postcards of Unitarian and Universalist Church Buildings
Searchable database of digitized images of nineteenth- and twentieth-century postcards picturing Unitarian and Universalist church buildings.
http://www.hds.harvard.edu/library/collections/digital/postcards.html