According to Joseph Allen, the question is often asked, "how did the records that Mormon gave to Moroni about 385 years after the sign of Christ's birth (Mormon 6:6) get to the hill called Cumorah in New York?" If, according to a Mesoamerican setting, the last battle was fought at the Hill Vigia (Hill Cumorah) which is located in Veracruz, Mexico, then Moroni must have carried the records to New York sometime after the final battle. The final battle was A.D. 385; Moroni's last entry was A.D. 421. That makes 36 years from the time of the last battle to Moroni's last dated entry. [Joseph L. Allen, Exploring the Lands of the Book of Mormon, p. 351]
The Book of Mormon student should note, however, that beyond the recorded date of 421 A.S. is a period of time that is unknown to us. Moroni's travels to New York might have been during this time period even though Moroni does say, "I soon go to rest in the paradise of God" (Moroni 10:34). [Alan C. Miner, Personal Notes]
“I Soon Go to Rest in the Paradise of God”
According to Jerry Ainsworth, if Moroni was born in A.D. 350, he would have been seventy-one years of age when he completed and buried this record in A.D. 421. It is therefore possible that after Moroni buried the plates, he lived long enough to be seventy-two, before being murdered by the Lamanites. This would have made him the same age as the nine disciples of Jesus when they died (see 3 Nephi 28:3). Seventy-two, being a multiple of a perfectly whole number, twenty-four, may reflect the three whole (perfect) members of the godhead, whom Moroni served so faithfully.
There are no primary sources that document how Moroni died. One third-hand account indicates that Brother Higgenson stated that Thomas Marsh told him that the Prophet Joseph Smith was reported to have said that Moroni died in a hand-to-hand sword combat with six Indians. After killing three of the six Indians, Moroni "became exhausted" and was killed by the fourth Indian, with whom he crossed swords. (Peterson, Moroni: American Prophet, Modern Messenger, 77).
What we do know with certainty, however, is that since Moroni appeared to Joseph Smith as a resurrected being, he did indeed die. [Jerry L. Ainsworth, The Lives and Travels of Mormon and Moroni, pp. 230-231]