The Oregon Trail migration, more correctly known as the Oregon-California Trail migration, is one of the most important events in American History. The Oregon-California trail was a 2,170 mile route from Missouri to Oregon and California that enabled the migrating of the early pioneers to the western United States. The first emigrants to make the trip were Marcus and Narcissa Whitman who made the trip in 1836. However, the first mass migration did not occur until 1843 when approximately 1000 pioneers made the journey at one time.