The Whitmans and the Spaldings started their journey as missionaries. During the journey, the two spreaded apart. While the Spaldings worked with the Nez Perce, the Whitmans worked with the Cayuse. The Spaldings successfully converted some Nez Perce leaders. On the other hand, the Whitmans were less successful.
While Spaldings were successfully converting Native Americans into Christians, the Whitmans were converting more and more Americans to the belief that Oregon was a pioneer's paradise. Many settlers followed Marcus to Oregon. Indians were overwhelmed by the number of Americans coming into the country side. The Whitmans were killed by the Indians, who thought the two were treating the whites more specially.
Contrary to the missionaries' goal, relatively few Indians were converted to Christians. Many died from diseases. The missionaries ended up opening the West to settlement.