Funfact: Did you know that The Temple square is one of the Most popular tourist attraction in the United States with 5 million tourist every year? It also ranks as top 15 most visited Tourist attraction in America. This 10 acre block located in the middle of downtown Salt Lake City is Utah's number one tourist attraction. But why did the Temple Took 40 years to build?
The temple construction took 40 years because General Johnston's army was coming and Brigham Young instructed the saints to bury the temple in fear the army could destroy it much as what happened to the Nauvoo temple. Until the temple was ready sealings took place on Ensign Peak in a cave.
The place was dedicated for that purpose. No major reconstruction was needed.
The granite that were used for the temple came from little cottonwood canyon 40miles from Salt Lake City. They were cut and hauled to the temple site by oxen carts and mule teams. The Washington D.C. was one of the last large temples constructed and is in the design of the Salt Lake Temple with the six spires.