The United States began as a group of 13 colonies controlled by Great Britain. These colonies won their independence during the American Revolution and became a unified country. Since that time the United States has continued to expand its borders. The Northwest Territory was conquered following the American Revolution, the Louisiana Territory was purchased from France, and the lands of California, New Mexico, and Texas were conquered after the Mexican-American War. All these conquered lands helped expand the borders of the United States and transform the country into a global force. Expansion into the western lands of the United States became a growing trend in the early 19th century and continued to gain popularity among Americans. These lands promised a new beginning for some people and for others an opportunity for great wealth. Western expansion also created conflicts among Americans. Competition for prime land, debates over slavery, and conflicts with Indians began to emerge with increasing expansion. The benefits and conflicts associated with Western expansion defined the area and its role in America. The western expansion of the United States created a number of benefits for the economy and its citizens. As Americans expanded into these lands, they gained additional land area along with the resources the land possessed. One of these precious resources that attracted Americans to the West was gold. During the mid-1800s, gold was discovered in northeastern California. This inspired a movement of many Americans to leave their homes to settle in the West in hopes of discovering gold. This gold rush attracted mostly single men to the unexplored western lands. Another resource that attracts...... half of the document......ta when it was accepted into the Union (Hewitt and Lawson 309-313). Other states also struggled with the issue of slavery in the West. California and the territories of New Mexico, Utah, Kansas, and Nebraska were all in dispute as to whether they should be admitted as free or slave states. These areas were above the line separating free and slave states, so under the Missouri Compromise, they should have been admitted as free states. However, with the annulment of the Missouri Compromise following the Dred Scott affair, the territories did not need to be admitted as free states. Settlers in these territories were mixed in their opinions on slavery and whether the enslavement of blacks should be allowed in the area. California was eventually admitted as a free state, and the territories of New Mexico, Utah, Kansas, and Nebraska would decide on slavery by popular sovereignty.