Impacts of U.S. Expansion

Expanding the Nation

The expansion of the United States is introduced by asking students to examine two maps: one showing the U.S. population growing from east to west over time, and the other showing Indigenous nations occupying the same land. This contrast invites students to consider how the growth of the United States created conflict and affected different groups of people. Cluster 1 explores how the United States acquired territory in the eighteenth and nineteenth centuries–through war, purchases, treaties, and annexations–with particular attention to how the United States. repeatedly failed to honor treaty commitments made to sovereign Indigenous nations. Students also examine how the question of whether to allow slavery in new territories divided the nation. The cluster formative assessment asks students to select one example of U.S. territorial expansion and complete a cause and effect graphic organizer analyzing the government decision: which groups were affected, what happened as a result, and why it created conflict.

Moving West

Students launch this cluster by analyzing the painting American Progress by John Gast, making observations and asking questions as an entry point into the concept of Manifest Destiny. Throughout the cluster, students analyze primary sources by considering who created them, why, and whose perspectives are present or missing. This builds their ability to evaluate a source’s credibility and point of view. They investigate the Santa Fe Trail as a key trade route into Mexican territory. Then, they examine how the Mexican–American War opened the door to mass westward migration. Next, they turn to the Transcontinental Railroad, analyzing primary sources across different perspectives to understand its far-reaching impacts. Students synthesize their learning in an Inquiry Circle by returning to the Supporting Question and expanding on it: Why did so many people move to the American West? Who was affected when so many people moved to the American West? In the Formative Assessment, students compare American Progress with [the painting] Reversing Manifest Destiny, examining how perspective shapes the story of U.S. Expansion.

The Injustices of Expansion

Cluster 3 focuses on the harm caused by U.S. Expansion into the ancestral homelands of Indigenous peoples andthat expansion’s impact on other groups, such as Mexicans and formerly enslaved people seeking freedom and equal opportunity. Students will work with a concrete definition of justice, and apply that idea to stories of people impacted by U.S. Expansion.