When was the Mexican-American War?

The war between the U.S. and Mexico spanned the period from April 25,1846 to February 2, 1848. The war resulted in Mexico's defeat and the loss of approximately half of its national territory in the north. The Treaty of Guadalupe Hidalgo was the peace treaty signed on February 2, 1848, between the United States and Mexico that ended the Mexican–American War (1846–48).