Final answer:
Mark Twain is often recognized as the "father of American Literature" because of his significant influence on American narrative and the development of a distinct American literary voice. William Dean Howells is known as the "father of American Literary Realism" and notably contributed to this genre.
Step-by-step explanation:
The "father of American Literature" is often considered to be Mark Twain. He earned this title due to his significant influence on American narrative and his use of distinctly American themes and language. This paved the way for a unique American literary voice that diverged from its British origins. Twain is best known for his novels The Adventures of Tom Sawyer and Adventures of Huckleberry Finn, the latter often referred to as the "Great American Novel" due to its profound impact on American literature.
Additionally, William Dean Howells is deemed the "father of American Literary Realism" for his contribution to the style of writing that presented a more realistic portrayal of life, in contrast to the Romantic era's excesses. Howells's influence extended through his roles as an author and editor, and through his promotion of fellow American authors. His novels, like A Modern Instance and The Rise of Silas Lapham, embody the realist tradition in American literature.