* His first published work, "Cup of Gold," was a historical novel released in 1929. It received mixed reviews and did not achieve commercial success.
* Steinbeck's breakthrough came with his novel "Tortilla Flat" in 1935. This book, set in the Salinas Valley of California, garnered critical acclaim and established him as a writer to watch.
* His subsequent novels, "Of Mice and Men" and "The Grapes of Wrath," further cemented his fame and solidified his position as one of the most important American authors of the 20th century.
So, while he had a book published before becoming famous, it was his later works that brought him widespread recognition and critical success.