Why is Huck Finn written in first person?

Can you elaborate on the reasoning behind Mark Twain's decision to write The Adventures of Huckleberry Finn from the first-person perspective? Was it to provide a more intimate and authentic narrative of Huck's journey down the Mississippi River? Or did he choose this point of view to give readers a deeper understanding of Huck's character and his struggles with morality and society? Additionally, how does the use of the first-person narrative enhance the overall themes and messages of the novel?