The First Unitarian Church was founded in 1890, and the beautiful building you are looking at was dedicated on September 4, 1927.
If you are a history buff, check out the Marriott Library online publication: https://uhslc.lib.utah.edu/timeline.
The First Unitarian Church of SLC nurtures and challenges the spiritual and intellectual journey for all generations and actively engages in building a progressive and just world. Love is the spirit of the Church, with service to one another and to the larger community its greatest concern. SLCUU.org