In Helaman chapter 3, we learn that the migrants did a lot of building. The Ammonites were innovative, and the record says that they moved to where there was not much timber. What were they to build with? They solved the problem innovatively by building structurally with cement. The cement they learned how to use was very high-quality cement—it was not just mortar holding blocks together. These migrants discovered and used a new technique.
There are several places in the western hemisphere where there are pits of natural dry lime plaster. It can be put in sacks and transported more easily than blocks of stone. When mixed with water, this natural lime makes a very high-quality cement. Several locations in Mesoamerica you can walk on today have slabs of cement poured 2,000 years ago that are in better condition than an average driveway today—mine included!
After the Book of Mormon was published in 1830, some people doubted that people in the ancient western world had become “exceeding expert in the working of cement.” Where were the remains of their cement structures? Subsequently, the discovery of such structures came to light. Teotihuacan, an enormous ancient archeological site in the Valley of Mexico, is one location where structures were constructed of cement. Archeologists can date the origin of those buildings. A master’s thesis written at Johns Hopkins University in the 1940s dated the introduction of concrete or cement structural building techniques to about the middle of the first century B.C. Indeed, the forty-second year of the judges was 50 B.C., precisely the middle of the first century B.C. I have liked to call this “concrete evidence for the Book of Mormon.” As a fact stated in the Book of Mormon itself, any proposed real-world location for the Ammonites’ relocation into a land northward needs to reckon with this remarkable detail included in Helaman 3:7. This use of cement must have been a very stunning invention. No wonder the Nephite records mentioned it, and Mormon—who came grew up in the land northward (Mormon 1:6)—preserved this detail in his abridgment.
Book of Mormon Central, “When Did Cement Become Common in Ancient America? (Helaman 3:7),” KnoWhy 174 (August 26, 2016).
Matthew G. Wells and John W. Welch, “Concrete Evidence for the Book of Mormon,” in Reexploring the Book of Mormon: A Decade of New Research, ed. John W. Welch (Salt Lake City and Provo, UT: Deseret Book and FARMS, 1992), 212–214.
John L. Sorenson, “How Could Joseph Smith Write So Accurately about Ancient American Civilization?” Echoes and Evidences of the Book of Mormon, ed. Donald W. Parry, Daniel C. Peterson, and John W. Welch (Provo, UT: FARMS, 2002).