FRÉMONT EXPLORATIONS. John Charles Frémont (1813–1890), Republican Party presidential candidate in 1856, became famous for leading five explorations of the American West between 1842 and 1854. Commissioned in 1838 as a second lieutenant in the Army Corps of Topographical Engineers, Frémont accompanied scientist and topographer Joseph N. Nicollet on expeditions of the upper Mississippi in 1838 and 1839. Backed by his father-in-law, Senator Thomas Hart Benton of Missouri, Frémont commanded his first major expedition in 1842, journeying up the Platte River to the South Pass and the Wind River Mountains. Topographer Charles Preuss and guide Christopher "Kit" Carson assisted Frémont on this trip, as they did on several sub-sequent expeditions.
In 1843–1844 Frémont made an immense journey encompassing most of the territory west of the Mississippi. Departing in May 1843 from St. Louis, Missouri, he traveled to the South Pass, made a southward loop to the Great Salt Lake, and moved north via the Snake River to Fort Vancouver. He then turned south, explored the western edge of the Great Basin, and made a risky midwinter crossing of the Sierra Nevada to California. After pausing at Sutter's Fort, Frémont moved south through the Central Valley, crossed the Tehachapi Pass and turned east. He crossed Nevada, explored Utah Lake and the Rocky Mountains en route to Bent's Fort on the Arkansas River, and arrived in St. Louis on 6 August 1844. Based on this expedition Frémont and Preuss produced the era's most accurate map of the region, clarifying the geography of the Great Salt Lake and giving the Great Basin between the Wasatch and Sierra Nevada ranges its name.
Now a national figure, Frémont departed for his third expedition in June 1845. Although ordered to make a limited reconnaissance of the Arkansas and Red Rivers, he headed across the Great Basin to California, arriving at the American River on 9 December 1845. The following spring he left California for Oregon, but for reasons that remain ambiguous returned in May 1846 to California, where he played a central role in the Bear Flag Revolt. Frémont's insubordination during the revolt resulted in his 1847 court-martial, after which he resigned his commission.
With private funds, Frémont embarked on another western survey in 1848–1849. This catastrophic expedition resulted in the death of ten men due to starvation in the San Juan Mountains. Frémont spent the next few years in California, tending to his business interests and serving as a senator in 1850–1851. In 1853–1854 he made his last expedition, another privately funded railroad survey searching for a southern route to the Pacific.
Frémont's romantic and colorful reports depicted the West as a fertile land rich with opportunity. Supporters of western expansion used the reports to justify their arguments, while emigrants read them as guides to their journey. Although Frémont's explorations increased scientific knowledge of the trans-Mississippi West, his expeditions were most significant for helping to spur American emigration to and acquisition of the region.
Herr, Pamela, and Mary Lee Spence, eds. The Letters of Jessie Benton Frémont. Urbana: University of Illinois Press, 1993.
Jackson, Donald, and Mary Lee Spence, eds. The Expeditions of John Charles Frémont. 3 vols. Urbana: University of Illinois Press, 1970–1984. Annotated edition of correspondence and reports, including two supplemental volumes and map portfolio.
Nevins, Allan. Frémont: Pathmarker of the West. New York: Ungar, 1962. Originally published as Frémont: The West's Greatest Adventurer (1928). Revised edition first published in 1939.
Richmond, Patricia Joy. Trail to Disaster: The Route of John C.Frémont's Fourth Expedition from Big Timbers, Colorado, through the San Luis Valley, to Taos, New Mexico. Denver: Colorado Historical Society, 1989.