Work on the building began in 1863, and the church's Semiannual General Conference was held there for the first time in October 1867, though the structure wasn't formally dedicated until 1875.

General conferences of the church were held there until April 2000, when the Conference Center became the new gathering place for the tens of thousands who come from around the world to attend each April and October.

During the Conference Center inaugural, it was noted the church could never build a structure large enough to house all those who wish to attend simultaneously. Apparently the same concerns were being voiced about the Tabernacle, even as its size awed visitors and members alike.

An article published in the journal Scientific American on June 8, 1867, titled, "The Great Mormon Tabernacle at Salt Lake," described the expansive structure and "the mechanical difficulties of attending the construction of so ponderous a roof."

It also noted that "as large as is the extent provided for the accommodation of the people — it is now feared that it will be too small and further accommodations will be necessary."

The writer noted that the "majestic, towering, self-supporting roof" would consume "nearly one million feet of lumber," a mind-numbing figure to observers of the time. Much of it became the wood lattice trusses that support the oval-shaped dome, but that early estimate was off by 50 percent.

The final figure, as reported in the April 2007 edition of the church's Ensign magazine, was 1.5 million board feet, hand-cut and transported via wagon or ox cart to the construction site, where the trusses were built and fitted into place using wooden pegs, rawhide strips and some metal bolts.

LDS President Gordon B. Hinckley told reporters and builders in 2004 that he wanted the basics of that pioneer craftsmanship to remain in place, to seismically retrofit the building without destroying its character.

Consequently, steel "sister trusses" were installed adjacent to the existing wood lattice trusses to "preserve the historic arch while providing the level of safety desired for gravity and seismic loads," according to the Ensign report.

Observers walking through Temple Square last year saw construction workers laying a new aluminum roof over the Tabernacle's distinctive dome, replacing a similar roof that was installed in 1947 for the centennial of the Mormon pioneers' entrance into the Salt Lake Valley.