We often say that the large plates of Nephi contained a secular history, and the small plates a spiritual history. Is that completely accurate? Let us look at 1 Nephi 19:6. What is the key point there? Nephi said it is all sacred: "Nevertheless, I do not write anything upon plates save it be that I think it be sacred." I think to Nephi all history was sacred because the hand of the Lord, His providence, was involved in guiding and directing the affairs of mankind. We might see a record as being more politically or economically focused, but Nephi never took God out of the situation. To put it in modern terms, whether the people prosper or perish has less to do with how the stock market is doing and more to do with their collective righteousness. To Nephi, even what we would call secular was sacred.
Book of Mormon Central, "Why Did Nephi Write His Small Plates? (1 Nephi 9:4)," KnoWhy 11 (January 14, 2016).