Expeditions to the West

Frémont assisted and led multiple surveying expeditions through the western territory of the United States. In 1838 and 1839 he assisted Joseph Nicollet in exploring the lands between the Mississippi and Missouri Rivers, and in 1841, with training from Nicollet, he mapped portions of the Des Moines River. From 1841 to 1846 he and his guide Kit Carson led exploration parties on the Oregon Trail and into the Sierra Nevada. During his expeditions in the Sierra Nevada, it is generally acknowledged that Frémont became the first Caucasian to view Lake Tahoe. He is also credited with determining that the Great Basin had no outlet to the sea. He also mapped volcanoes such as Mount St. Helens.

In late 1846 Frémont, acting under orders from Commodore Robert F. Stockton, led a military expedition of 300 men to capture Santa Barbara, California, during the Mexican-American War. Expecting to be ambushed in Gaviota Pass by the entire Mexican army, he led his unit over the Santa Ynez Mountains at San Marcos Pass during the rainy night of December 27, 1846, and captured the Presidio, and the town, from behind. The rumor of the ambush turned out to be false: the army had been at Los Angeles with General Andrés Pico. General Pico, recognizing that the war was lost, later surrendered to him rather than incur casualties.

Expedition Routes

Fremont Expedition Flag

1856 US campaign banner

Civil War

Frémont served as a major general in the American Civil War and declared martial law in Missouri. This declaration led to a conflict with Abraham Lincoln and led to Frémont's removal from command in the West on November 2, 1861. He was re-appointed to a different post (in West Virginia), but lost several battles and resigned his post.

Later life

In 1866, Frémont reorganized the assets of the Pacific Railroad as the Southwest Pacific Railroad, which a year later was repossessed by the U.S. state of Missouri.

Frémont was appointed Governor of the Arizona Territory from 1878 to 1881. He died of peritonitis in a hotel in New York City and is buried in Rockland Cemetery, Piermont-on-Hudson, New York.

Frémont collected a number of plants on his expeditions, including the first recorded discovery of the Single-leaf Pinyon by a Caucasian. The standard botanical author abbreviation Frém. is applied to plants he described.