The First Unitarian Church of Salt Lake City records (1891-2010) is a rich collection of source materials, containing primarily original documents tracing the history and activities of the Unitarian Church in Salt Lake City. It is organized into 221 boxes of records dating from its founding in l89l up to 2010. The Unitarian Church has been an advocate of many causes and has played a vital cultural role in the Salt Lake City area.

The Philip S. Thacher papers (1971-1989) contain biographical materials, photocopy of a scrapbook detailing his activities and a photocopy of a letter to the First Parish Church of Needham, Massachusetts "on its Bicentennial Anniversary." Thacher was a pastor of the First Unitarian Church of Salt Lake City, Utah.