Final answer:
The Oregon Trail was first traveled in the early 1840s by American settlers moving westward, a journey that played a significant role in the United States' territorial expansion.
Step-by-step explanation:
The Oregon Trail was first traveled in the early 1840s. It became a key route for those participating in westward expansion and was famously traveled by American pioneers seeking fortune and new opportunities in the Oregon Territory. Thousands of settlers undertook the perilous journey, contributing to the United States' territorial claims and the popularization of the concept of Manifest Destiny.
By the mid-1840s, around 5,000 Americans had settled the Oregon Territory, bolstering the U.S. position in the region. It's worth noting that while the journey across the approximately 2,000-mile trail was fraught with danger—including diseases like cholera and dangers from accidents and river crossings—conflict with Native Americans was uncommon and often initiated by the immigrants themselves.