How did the Gentiles get their hands on the brass plates from the Jews as said in 1 Nephi 13? Any historical events regarding the book?
Thank you for asking this question. The “brass plates” in the Book of Mormon specifically are referring to the plates that Laban had in his possession. The Gentiles never obtained the brass plates. The brass plates remained with the Nephites. As to where the brass plates are now, we don’t know. That has not been revealed.
Please notice the language in the Book of Mormon, 1 Nephi 13:23, referencing the plates of brass,
“The book that thou beholdest is a record of the Jews, which contains the covenants of the Lord, which he hath made unto the house of Israel; and it also containeth many of the prophecies of the holy prophets; and it is a record like unto the engravings which are upon the plates of brass, save there are not so many; nevertheless, they contain the covenants of the Lord, which he hath made unto the house of Israel; wherefore, they are of great worth unto the Gentiles.”
The Book of Mormon is referring to a “book” (or potentially books) that contains the records of the Jews. We further recognize that this book is a “record like unto” engravings that are upon the brass plates or “plates of brass.”
You only have to look at our current history and how the Holy Bible was compiled to understand what book(s) the Gentiles received which the Book of Mormon is probably referencing.