The war officially ended on February 2, 1848. signing in Mexico of the Treaty of Guadalupe Hidalgo. The contract has expanded an additional 525,000 square miles in the US territory. The Americans paid 15 million dollars.
The main reason of the Mexican-American War, westward expansion, economics, and slavery. American citizens in the south wished to gain more "slave states" in order to increase their political power.
The right answer is C.Resolved the slavery in the US