Why was the U.S. Congress reluctant to declare war on Mexico?
They wanted to buy the land through diplomacy.
It would tip the balance between states in favor of slavery and those against it.
They didn’t want to participate in a war of aggression to claim land.
They were concerned about the financial and human costs of the war.
They were unsure if they had the constitutional authority to declare war.
They were hesitant to engage in a conflict with a neighboring country.