Many people are responsible for the westward expansion of the United States. Meriwether Lewis and William Clark were among the first Americans to explore and accurately map the Western territories. During their expeditions, they were aided by a Shoshone woman named Sacagawea and her French-Canadian husband Toussaint Charbonneau, during which they served as translators. Their expedition enabled thousands of settlers to move west. Jorge Donor was a settler who migrated west with a group of settlers (known as the Donor Party) to settle there. During the expedition, Jorge Donor decided to take a shortcut called the Hastings Cutoff to eliminate travel time (ironically, this lengthened their journey and caused many tragedies). In order to survive, they began eating their animals and then evolved into cannibalism to survive until they were rescued. The California Gold Rush brought many settlers west in search of their fortune. The first person to discover gold in California was James Marshall. It was thanks to his discovery of gold that thousands of people flocked to California. Although in the East many promises of wealth were made, not everyone would play golf. An example of this is Jean Nicholas Furlough who came to California from Belgium to become rich although he never did. Settings Western expansion occurred in many places west of the Mississippi. One of the most important settings was the Louisiana Purchase which was purchased in 1803, the 828,000 square miles of land almost doubled the size of America...... middle of paper.. ....nize and colonize the west in the end, some of them were intended to obtain new land, minerals and finally expand the American territory. Many things were done to settle and colonize the West, such as wars, treaties, and good old land exploration to settle the land. The westward expansion of the United States had many costs, including the deaths of 20,000 settlers due to hardship during the colonies, the deaths of 13,283 soldiers during the Mexican-American War, and hundreds of millions of dollars wasted on wars, treaties and land sales. On the optimistic side, there are many benefits to American expansion. The United States has doubled its size, GDP, and population during this period. The United States has also gained the respect of other countries and gained more trading partners. Westward Expansion Had Many Effects on American Culture.