Final answer:
The majority of Americans seeking to farm or start anew in the mid-1800s used the Oregon Trail, which was the most famous route for westward expansion during that time, with over 400,000 settlers using it between 1845 and 1870.
Step-by-step explanation:
Many Americans who headed out west in the mid-1800s to farm or to get a new start mainly used the Oregon Trail. This trail became the most famous of the western routes and was a key path for settlers looking for open lands, economic opportunity, and greater freedom. The Oregon Trail was approximately 2,000 miles long, originating in Independence, Missouri, and traversing across plains and the Rocky Mountains before reaching the fertile valleys of Oregon. During the peak migration period between 1845 and 1870, it is estimated that over 400,000 settlers took to the Oregon Trail in search of a new beginning. The trail's significance also lies in how it fostered cooperation and coordination among the wagon trains, which was vital for their success in the face of dangers like disease and accidents.