One lasting polltical Impact of the Mexican-American War was slavery becoming legal in new vestern territories entering the U.S. increased tension between northern and southern states in the U.S. the dramatic increase in taxes in order to pay for the war a loss of American lands to the Mexican government in modern New Mexico.

The lasting political impact of the Mexican-American War was **increased tension between northern and southern states in the U.S.**<br /><br />The newly acquired territories from Mexico reignited the debate over the expansion of slavery. Would these new territories be free or slave states? This question further divided the nation along sectional lines and contributed significantly to the growing tensions that ultimately led to the Civil War.<br />