What was the name of the major route used by pioneers traveling to Oregon in the 1840s?

The major route used by pioneers traveling to Oregon in the 1840s was indeed the Oregon Trail. This trail was a significant pathway for thousands of settlers seeking new opportunities in the West as part of the larger westward expansion movement. Spanning around 2,170 miles from Missouri to the Oregon Territory, the Oregon Trail was heavily traveled during the 1840s and 1850s as families sought fertile land and a new start away from the crowded conditions of the East.

The Oregon Trail is distinguished from other routes, such as the California Trail, which led to the gold-rich regions of California, or the Santa Fe and Old Spanish Trails, which were primarily trade routes. Each of these trails served different purposes and populations, but the Oregon Trail was specifically associated with the settlement of the Oregon Territory, making it the correct answer for this question regarding the route taken by pioneers during that time period.