 Whipple was directed to lead one of those surveys along the 35th parallel from Fort Smith, Arkansas to Los Angeles.The Whipple expedition left Fort Smith on July 15, 1853 with a group of seventy men including soldiers, teamsters, and scientists.Among the scientists were John Milton Bigelow, a medical doctor and botanist; Jules Marcou, a Swiss geologist; and Balduin Möllhausen, a German artist and a protege of Alexander von Humboldt.