John Steinbeck allowing Steinbeck to spend a full day on the set of "The Grapes of Wrath" and the next day on the set of "Of Mice and Men." In the 1930s and 1940s, Ed Ricketts strongly influenced Steinbeck's writing. Steinbeck frequently took small trips with Ricketts along the California coast to give himself time off from his writing and to collect biological specimens, which Ricketts sold for a living. Their joint book about a collecting expedition to the Gulf of California in 1940, which was part travelogue and part natural history, published just as the U.S. entered World War II, never
John Steinbeck found an audience and did not sell well. However, in 1951, Steinbeck republished the narrative portion of the book as "The Log from the Sea of Cortez", under his name only (though Ricketts had written some of it). This work remains in print today. Although Carol accompanied Steinbeck on the trip, their marriage was beginning to suffer, and ended a year later, in 1941, even as Steinbeck worked on the manuscript for the book. In 1942, after his divorce from Carol he married Gwyndolyn "Gwyn" Conger. With his second wife Steinbeck had two sons, Thomas ("Thom") Myles Steinbeck (1944–2016) and