Title: Conclusion: The Effects of Westward Expansion | Boundless US History
Headings: Conclusion: The Effects of Westward Expansion
Conclusion: The Effects of Westward Expansion
Conclusion: The Effects of Westward Expansion
Learning Objectives
Key Takeaways
Key Points
Key Terms

Content: After U.S. victory, the Mexican Cession added nearly half of Mexico’s territory to the United States, including New Mexico and California, and established the U.S.–Mexico border at the Rio Grande. The California Gold Rush of 1849 rapidly expanded the population of the new territory, while also prompting concerns over immigration, especially from China. Efforts to seize western territories from native peoples and expand the republic by warring with Mexico succeeded beyond expectations; few nations had ever expanded so quickly. However, this expansion led to debates about the fate of slavery in the West. Increasingly, the South came to regard itself as under attack by radical northern abolitionists, and many northerners began to speak ominously of a southern drive to dominate U.S. politics for the purpose of protecting slaveholders’ human property. As tensions mounted and both sides hurled accusations, national unity frayed. Compromise became nearly impossible and antagonistic sectional rivalries replaced the idea of a unified, democratic republic. Tensions between the North and South ultimately led to the collapse of American democracy and a brutal civil war. CC licensed content, Shared previously
Curation and Revision.