A huge block of new territory was acquired—approximately 525,000 square miles
The Mexican War and the tide of expansionism it unleashed underlined the political control exercised by the South in American political affairs
The addition of new lands touched off new and bitter debates on the slavery issue, as many had predicted
The Americans suffered heavy losses; the nearly 13,000 dead included only about 1,700 in combat—the rest succumbed to rampant disease
The war was a proving ground for young military officers (Jackson, Lee, Meade, Sherman, for example) who would soon put their skills to work in the American Civil War.
