John C. Frémont's document box, n.d.
Dispatch boxes like this one, carried by mules over difficult terrain, conveyed reports and correspondence composed during Frémont’s expeditions. Though some material was lost to accidents and bad weather, most of the information was published in Frémont’s report to the U.S. Senate. To meet popular demand, the publisher issued more than 24 editions by 1860.
Manuscript Division, Library of Congress
John C. Frémont
As an explorer, Army officer, and politician, John C. Frémont was a key figure in the nation’s westward growth. His expeditions charted previously little known territory for Congress and settlers migrating west. His father-in-law, the expansionist-minded Senator Thomas Hart Benton of Missouri, was instrumental in obtaining congressional funding for the expeditions and report that furnished Congress with facts for legislation on western territories. Frémont served as California’s first U.S. senator from 1850 to 1851. He ran unsuccessfully as the antislavery Republican Party’s first presidential candidate in 1856.