Source S The Mexican-American War of 1846-1848 resulted in a massive expansion of American territory. Under the Treaty of Guadalupe Hidalgo, Mexico ceded ne...

This is a "How far do you agree?" question worth 10 marks, requiring a balanced argument that uses the source and your own knowledge to evaluate whether westward expansion brought more problems than benefits.

What the source contributes: The textbook excerpt shows that the massive territorial gains from the Mexican-American War (1846-1848) immediately intensified the most dangerous political question: whether slavery would be permitted in new territories. The Wilmot Proviso (1846) attempted to ban slavery from lands acquired from Mexico but failed in the Senate. The Compromise of 1850 offered only a temporary solution. These disputes pushed the nation toward civil war.

Building a case for problems:

• The slavery debate worsened with each territorial acquisition, leading to the Kansas-Nebraska Act (1854), the violent conflict known as "Bleeding Kansas," and ultimately the Civil War (1861-1865), which cost over 600,000 lives.
• Expansion caused the forced removal and decimation of Native American peoples. The Indian Removal Act (1830) led to the Trail of Tears. Military campaigns on the Great Plains destroyed traditional ways of life, and the reservation system confined surviving populations to marginal lands.
• The Mexican-American War itself was controversial. Abraham Lincoln and other Whigs opposed it as an unjust war of conquest against a weaker neighbour.

Building a case for benefits:

• Expansion enormously increased American territory and natural resources.
• The discovery of gold in California (1848) stimulated economic growth and population movement.
• The Homestead Act (1862) provided land to settlers, encouraging agricultural development of the Great Plains.
• The transcontinental railroad (1869) linked the economy and facilitated trade.
• The United States became a continental power with access to Pacific trade routes, laying the foundations for its rise as a global economic power.

Reaching the highest level (9-10 marks): Level 4 requires a sustained analysis that weighs problems against benefits rather than simply listing both. Use the source as a springboard, then develop your argument with specific own knowledge. A strong conclusion might argue that expansion brought significant material benefits and contributed to American economic power, but these gains came at enormous human cost to Native Americans and Mexican communities, and the failure to resolve the slavery question directly caused the Civil War. Avoid one-sided arguments; the examiner is looking for genuine engagement with both sides.