Which of the following is an example of a federal power in the United States?

Declaring war is an example of a federal power in the United States. According to the United States Constitution, the power to declare war rests with the federal government specifically with the Congress. The President, as the Commander-in-Chief of the military, has the authority to direct military forces, but the decision to officially declare war must be made by Congress. This division of power helps to ensure checks and balances and allows for democratic decision-making regarding matters of war and national security.