How many letters does the top answer for “wrote of mice and men” have?

The most common answer is steinbeck (9 letters).

Crossword clue: wrote of mice and men

1 answer found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).

steinbeck 9 letters wd-fact-v3

United States writer noted for his novels about agricultural workers (1902-1968)

author of of mice and men 50% similar → steinbeck

wrote far from men 50% similar → mortensen

wrote the hollow men 50% similar → eliot