The Missouri River holds an important spot in the history of the American West. Indeed, it was the jumping off point for all of the major trails that hundreds of thousands of people followed west, including the Oregon Trail and Mormon Trail. Even the Pony Express started on its banks at St. Joseph, Missouri.
And riverboats? Well, during the mid to late-1800s they connected the American West with both the eastern and southern parts of the country. So, not only goods, but also people, relied on them for transportation.