Which conflict resulted in the united states gaining more southwestern territory, including california, nevada, and utah?

The appropriate response is Mexican-American War. It was an outfitted clash between the United States of America and the United Mexican States from 1846 to 1848. It followed in the wake of the 1845 American addition of the free Republic of Texas, which Mexico still considered its northeastern area and a piece of its domain after its true withdrawal in the 1836 Texas Revolution 10 years sooner.