James Marshall left his family’s home in New Jersey as a young man and, like so many others, began a migration west. After contracting malaria while living in Missouri he was advised to go further west, and in 1845 he arrived in California. He worked a number of different jobs and served in the army during the Mexican-American War in 1846. When he got out, a man he had earlier befriended, John Sutter, entered a partnership agreement with Marshall to build a sawmill.