Western Expansion refers to the period in the 19th century when the United States expanded its territory westward across North America. This movement was driven by the belief in Manifest Destiny, the idea that Americans were destined to spread across the continent. Key events during this time included the Louisiana Purchase, the California Gold Rush, and the establishment of the Oregon Trail. As settlers moved west, they faced various challenges, including conflicts with Native American tribes and harsh environmental conditions. The expansion led to significant changes in the landscape and culture of the region, as new towns and infrastructure developed, and the Transcontinental Railroad was built to connect the east and west coasts.