The youngest child of amasa coleman lee based a book character on which of her childhood friends?

Truman Capote.

Explanation:

Nelle Harper Lee was the author of 'To Kill a Mockingbird.' He was the daughter of lawyer Amasa Coleman Lee. She was the youngest child of Amasa Coleman and Frances Lee.

Nelle Harper Lee based the character of Dill Harris in 'To Kill a Mockingbird' on her childhood friend Truman Capote. Truman Capote was also an American Novelist. Lee and Capote shared a lifelong friendship. They were not just friends but also neighbors.

Truman, also based the character of Idabel in 'Other Voices, Other Rooms', on his friend and neighbor, Lee.

Lee was born in Monroeville, Alabama and Capote was sent to Monroeville after the divorce of his parents where he was taken care of by his mother's relative.

So, the correct answer is Truman Capote, childhood friend of Lee on whom she based one of a book character.