[5] Established in 1846 as Fort Lewis and relocated 15 miles downstream in 1847 by Alexander Culbertson, who worked for Auguste Chouteau and Pierre Chouteau, Jr. of St. Louis, the original fort was the last fur trading post on the Upper Missouri River,[6][7] which soon made it an important economic center.

For 30 years, the port attracted steamboats carrying goods, merchants, gold miners and settlers, coming from New Orleans, Memphis, St. Louis, Hannibal, Bismarck, and Kansas City, among other places.

[6] As the eastern terminus for the 642-mile-long Mullan Road, completed by the United States Army in 1860, and at the head of navigation of the Missouri River, Fort Benton was part of the overland link between the Missouri and the Columbia River, with its own head of navigation at Fort Walla Walla in Washington.

[10] Steamboat travel to Fort Benton from St. Louis, Missouri, helped broadly fuel the development of the American West between 1860 and 1890, when it was supplanted by railroad transport.

[9] It was served by numerous well-known "mountain boats" (designed specifically for the Missouri River), including the Yellowstone and the Far West, and their famed captains, Joseph LaBarge and Grant Marsh, respectively.

[12][13][14] Fort Benton's importance in trade was superseded by the construction of transcontinental railroads in the late 19th century.

In 1867, Fort Benton was the site where Union General Thomas Francis Meagher, then acting governor of Montana Territory, fell overboard from his steamboat and drowned in the river; his body was never recovered.

[15][16] In the same year, Mountain Chief's brother and a teenage boy were assassinated in Fort Benton, supposedly in retaliation for the death of a white cattle rancher near to the town.

In 1870, a group of 10 Blackfeet Indians would be killed by Fort Benton soldiers and vigilantes for the alleged crime of cattle raiding.

[15] Fort Benton is located off U.S. Route 87 According to the United States Census Bureau, the city has a total area of 2.07 square miles (5.36 km2), all land.

[18] The community sits in a narrow river valley on the west bank of the Missouri River and is in a geographic area known as the Golden Triangle (one of several dozen folk regions of Montana) due to the strength of the wheat industry of the region.

The long summer days (due to being at almost 48 degrees N latitude) and fertile soil of the area (due in part to ash deposits from the Elkhorn Volcanics to the south) leads to exceptionally "hard" wheat (high protein content) thriving in the area.

Fort Benton experiences a semi-arid climate (Köppen BSk) with cold, dry winters and hot, wetter summers.