Fremont, popularly known as the “Pathfinder,” was instrumental in opening the American West. In 1842, Fremont was sent out by the U.S. Government to explore what soon came to be known as the Oregon Trail, as far west as the South Pass through the Rockies. The following years, Fremont was sent out again, at the instigation of Senator Thomas Hart Benton (Fremont’s father-in-law) to further explore the northwest part of the country, following the Oregon Trail all the way to the Pacific Ocean. In 1845, the government issued a report of these two expeditions which covered vast lands between the Missouri River and the Pacific Ocean. Through this report Fremont achieved great fame, leading to his election as Senator from California and later to his selection as the first Presidential nominee for the Republican Party. This report is one of the monumental works on Western exploration and the views from it are some of the earliest first-hand images of what was then an almost completely unknown American West.