Complex sentence: Dr. John Townsend, his wife, Elizabeth, and her younger brother, Moses Schallenberger, were going west because he was a man of vision and wanted a chance at grand adventure and opportunity in California.
Split into simpler sentences: Dr. John Townsend, his wife Elizabeth, and her younger brother Moses Schallenberger, were also going west. A man of vision, Townsend wanted a chance at grand adventure and opportunity in California.