St. George Temple Foundation — Miracle of the Mexican War Cannon

In 1871, at the commencement of construction for the St. George Temple in Utah, builders discovered the southeast corner of the chosen site was a swampy bog with high groundwater that would not support a heavy structure. Traditional methods failed to stabilize the ground. Under the direction of Erastus Snow (presiding over the Cotton Mission) and with Brigham Young involved in the project, the pioneers located an old iron Mexican War cannon and, by what was regarded as divine inspiration, converted it into a makeshift pile driver. Workers hoisted the heavy cannon and dropped it repeatedly to ram and pack volcanic rock into the marshy earth—accounts report packing as much as a thousand tons of rock—until a solid foundation was formed. This “remarkable providence” allowed the first temple in the Utah Territory to be completed on a site many had deemed physically impossible. The episode is documented in Albert E. Miller’s Immortal Pioneers and is recounted in DUP History Collection materials and later summaries of the event.

Fuller account of this event (as retold in St. George Temple, Washington County Historical Society):

Thousands of tons of small rocks were first placed in the marshy soil. Workers then pounded the huge quarried volcanic blocks on top of the small ones. Temple builders developed a pile driver by encasing a field artillery cannon from the Mexican War in heavy ash timbers bound by iron bands. By this tedious and laborious method, a firm foundation was created that has served to keep the building solid and unharmed through nearly a century and a half of elements, including a major earthquake in 1992 of 5.7 magnitude on the Richter Scale. The work was slow - draining the ground and pounding each stone until the pile driver bounced three times - indicating that the footing was solid.