The Lewis and Clark Expedition (1804–06) benefited from a number of fortunate circumstances and events. It was a very successful expedition and only one explorer perished.
First, the mission was lucky to have two remarkable leaders who worked well together. William Clark had been Meriwether Lewis's superior during Indian battles years before. Lewis, chosen to command the expedition, wanted Clark as co-commander. This request was refused. In spite of this, the two men worked as co-leaders, and there was no rivalry between them.
Second, luck always seemed to be with them when they encountered difficulties. For example, in 1805, the group reached a fork in the Missouri River. Luckily, they chose the southern route—the correct way.
Third, almost all of the Native Americans they met were amicable, and the tribes provided the explorers with food, shelter, horses, information, entertainment, and women. They also taught them hunting and how to make clothing from deer hides.
And finally, the aid given to the expedition by Sacagawea, a Shoshone woman, was indispensable. Little is known of her background or her life after the expedition. However, during the journey across America, she ably served as interpreter and guide, carrying her newborn son along with them.