The American author known for the novel "To Kill a Mockingbird" is Harper Lee. This novel, published in 1960, received critical acclaim and won the Pulitzer Prize for Fiction in 1961. It addresses themes of racial injustice, morality, and growing up in the American South through the eyes of a young girl named Scout Finch. Lee's portrayal of socially charged issues resonated with readers and has made her book a staple in American literature, leading to its ongoing relevance in discussions about race and ethics.