Benjamin Bonneville was born in France, the godson of none other than Thomas Paine, who called the boy “Bebia.” Paine had lived with the Bonnevilles in France during much of the 1790s, so when that family fell under the persecution of a rising Napoleon, Paine invited them to live with him in the United States. This famous revolutionary thus paid for young Bonneville’s passage to America when the boy was only 7. Upon Paine’s death, he left most of his New York estate to the boy’s mother, Marguerite, who had served as Paine’s nurse during his final years. In this way, Bonneville grew up as an American.
During the War of 1812, a teenaged Bonneville attended West Point, then spent time on assignment at, among other places, Fort Smith, in Arkansas Territory. He got his first taste of the frontier there, followed by appointments across the Mississippi in “Indian Territory” (modern Oklahoma) and Missouri. In Oklahoma, Bonneville spent evenings at the home of a fellow Frenchman, fur trader Auguste Chouteau, who, along with other traders and trappers, regaled Bonneville with stories of life in the mountains of the “Far West.”
In Missouri, while stationed at Jefferson Barracks, Bonneville came across the writings of New England schoolteacher Hall Kelley, whose articles advocated the settlement of Oregon country, and included maps and guides to accomplish this goal. Bonneville, already nursing ambitions to make his stamp on the West, was intrigued. He was possessed, wrote his famous biographer, Washington Irving, a few years later, of a “susceptibility to the grand and beautiful.”
Captain Bonneville met personally with Kelley, who was at that moment organizing several expeditions to Oregon. Although Bonneville was still in the Army, Kelley asked him to lead an expedition, and he agreed. However, Bonneville was one of only a few who did agree, and eventually plans for this first expedition were shelved. Bonneville needed more men, and also permission from the military for a leave of absence.
His plans with Kelley having failed, the determined Bonneville now approached the Army’s top general, Alexander Macomb, arguing that he should be granted leave in order to carry out an important exploration in the West—exploration that would produce invaluable intelligence on Oregon country (much of which was at that time contested by Britain). The eager captain must have won over the commanding general, who granted his request, with the understanding that Bonneville would treat his task as an intelligence-gathering mission. He was to pose as a fur trader, all the while amassing information on Oregon’s native peoples, geography, climate, soils, minerals, and anything else potentially useful. Several powerful American fur interests also came forward to bankroll the venture.
In 1832, Bonneville left western Missouri with 20 wagons and over 100 men, including mountain man and Santa Fe Trail veteran Joseph Walker. This large group made its way along the Missouri and Platte Rivers, the latter leading them into what we now call Wyoming. All the while, Bonneville marked their trail and the landscape’s features on his map, took regular temperature readings, and noted mineral deposits and other observations. Leaving the Platte River Trail, Bonneville and company made their way west through country inhabited (and contested) by Shoshone, Crow, Blackfeet, Cheyenne, Arapaho, and other native nations and bands.
Along the way, Bonneville ordered the wagons to form a defensive square in the evenings, a practice mimicked for safety by later wagon trains. By mid-July, the party could finally see the Rocky Mountains, and in August they reached the Green River. There, they established Fort Bonneville, a fortified winter camp, although there were ambitions that it might double as a fur trading post. But they rather quickly abandoned the fort as a result of its high altitude—sure during the winter to invite unremitting snowfall. Undeterred, Bonneville moved on. By September he had founded a new fort along the Salmon River in modern-day Idaho, where the group hunkered down in the cold to await spring.
As temperatures finally began to rise again early the next year, Bonneville made a momentous decision—to this day scholars aren’t certain of its origins. He ordered Walker to travel in the direction opposite Oregon country—heading south, toward the Great Salt Lake—hoping for good fur trapping, but also with the goal of identifying a route to California. Walker and his party trudged across some of the bleakest terrain in North America—the salt flats west of the Great Salt Lake—before stumbling upon the Humboldt River. This route led them across what we now call Nevada, where they continued on to the base of the imposing Sierra Nevada.
Ascending those steep peaks, Walker and his men wandered through the high country, seeking a passable way down the western side. Just as some were losing hope, they came upon a river, the Stanislaus, which they followed down the western slopes into the long, flat Central Valley of California. Later, Walker returned east by heeding the advice of native peoples in the region. His route through the Sierra, now called Walker Pass, constituted a main artery into California for decades. But Walker had failed to bring home a sizable fur haul, and Bonneville apparently considered the expedition a failure.
Bonneville helped blaze what would later become the Oregon Trail, but neither he nor Walker could have known that they had carved out a path destined to be followed by tens of thousands of gold-seeking prospectors, settlers, and other pioneers. That influx, in turn, would give quick birth to the state of California, with political repercussions echoing right up to the bloody Civil War.
This article was originally published in American Essence magazine.