When he reached his late 60s, he recounted his experiences in a book, "Sixty Years in California." The book was so well-received it became required reading for California schoolchildren. He wrote about meeting with the Russians of Fort Ross. He sailed up the Sacramento River with Capt. John Sutter, who was looking for the right spot to build a fort. Davis described the way the local Mexican government worked. He wrote about the visit of the U.S. Exploratory Expedition led by Commodore Charles Wilkes in 1841. But Davis wasn't satisfied with his book. When he reached his 80s he started writing about his 75 years in California. He wrote and wrote at his San Francisco business house. Then came the 1906 earthquake, and his 1,200-page manuscript disappeared; only his notes were left. It was a loss from which he never recovered. Davis died in 1909 at his daughter's home in Hayward. His children gathered his notes and took them to publisher John Howell, and Davis' "Seventy-five Years in California" saw the light in 1929