John Charles Frémont (January 21, 1813-July 13, 1890) was a military officer, an explorer, and the first candidate of the United States Republican Party for the office of President of the United States.
Frémont was born in Savannah, Georgia. In 1841-1846, he led exploration parties on the Oregon Trail and into the Sierra Nevada. On January 16, 1847 he was appointed Governor of the new California Territory following the Treaty of Cahuenga which ended the Mexican-American War in California. He served briefly (from 1850 to 1851) as a Senator from California. In 1856 the new Republican Party nominated him as their first presidential candidate, but he lost (see U.S. presidential election, 1856) to James Buchanan.
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.