The United States' boundaries have expanded over the centuries- and at the same time, Americans' ideas about their country have grown as well. The nation the world knows today was shaped by centuries of thinkers and events. In the 1830s, over fifty years after the United States had won its independence from Britain, Americans were still delighted with their young country. That sense of hope and freedom are still a part of the United States today. As you learn about the settlers who rode the Oregon Trail to new land in the West, you will gain a better understanding of how America became America. Book jacket.