The westward expansion of the United States during the 19th century was a pivotal moment in American history, characterized by the migration of settlers into the vast territories beyond the Mississippi River. This movement was driven by a variety of factors, including the desire for new opportunities, the promise of fertile land, and the belief in Manifest Destiny—the idea that Americans were destined to expand across the continent. As settlers ventured west, they faced numerous challenges, including harsh weather conditions, difficult terrain, and conflicts with Indigenous populations. These factors played a significant role in shaping the experiences of those who undertook the arduous journey, including the ill-fated Donner Party.

The journey west was marked by a series of overland trails, the most notable being the Oregon Trail and the California Trail. These routes provided pathways for thousands of emigrants seeking a new life. The California Trail, in particular, became a vital artery for those drawn by the allure of gold and the promise of prosperity. However, the journey was fraught with dangers, including disease, starvation, and the unpredictability of the elements. The Donner Party, a group of families and individuals who set out for California in 1846, would become one of the most infamous examples of the perils associated with westward migration.