Answer:
correct me if wrong, but I think it was the Pearl Harbor
Explanation:
President Truman, along with many prominent politicians at the time, believed the United States should sign the treaty because he thought it would prevent another World War II, but most importantly the spread of communism.
He was afraid that south korea would also become a communist nation. he wanted to prevent the spread of communism.
Answer:
It banned slavery in the territories acquired after the War with Mexico
.