War with which western nation reduced Mexico's territory by about half?

The Mexican-American War (1846-1848) ended with the Treaty of Guadalupe Hidalgo, in which Mexico was forced to cede over 500,000 square miles of territory to the United States. This massive land transfer, known as the Mexican Cession, reduced Mexico's total land area by roughly half. Wars with France, Spain, or Portugal did not result in this scale of territorial loss.