The first church building the Mormons built was the Tabernacle, built while the rest of the USA was involved in the Civil War. Utah was a territory at the time, not a state, so the War did not affect the Mormons to any significant degree.
The Tabernacle has a very distinct dome-like appearance.
The roof was originally sheathed in tin, which was later replaced by aluminum.
The structure was essentially built to house a pipe organ which, ultimately had over 11,000 pipes. It is massive.
The Mormon Tabernacle Choir, now consisting of 360 singers, performs every Sunday morning. The choir is broadcast on the radio, TV and cable weekly and is the longest continual broadcast in the world, having performed since 1929.