William Roberts' letterbook contains his retained copies of 29 letters written to his wife, sons, daughter, and daughters-in-law between the time of his departure from Boston and his establishing camp along the Merced River. His early letters are filled with fine descriptions of the sea voyage and the ports of call in the Azores and Chile. They reflect his close family relationships and his growing sense of religious fervor. Roberts is at his best as a writer, though, when describing the economic instability and amorality of Gold Rush San Francisco. But, interestingly, as he spends more time in California, and begins to salt away money through mining, the religious sentiments decrease, and he begins to express the benefits of gold mining as an occupation. In the end, Roberts writes that he is planning to delay his return to Rhode Island, ostensibly to make even more money for his family, but indicating that the free life of the gold mines, even with its amoral aspects, is better than life back east.