During the second half of the 1800s, the united states gained control of numerous territories in the west. which event hastened this process? a. massacre of american indians at wounded knee in 1890 b. passage of the compromise of 1850 c. us victory in the mexican-american war in 1848 d. discovery of gold in the klondike in 1896

The correct  answer is C: US victory in the Mexican-American War in 1848.

The war between the United States and Mexico resulted in Mexico losing 55 percent of its national territory to U.S. conquest: not just Texas, but the modern states of California, New Mexico, Arizona, Utah, and parts of Colorado and Wyoming as well.

that is probably something for you to answer