Final answer:
Congress's powers are delegated by the U.S. Constitution, including enumerated, implied, and inherent powers. These powers enable Congress to influence both domestic and international policy and are vital for the government's functioning.
Step-by-step explanation:
Congress only has those powers delegated to it by the U.S. Constitution. This principle is evident in the Constitution's specific granting of legislative powers to Congress, consisting of the Senate and House of Representatives. The powers described in the Constitution are known as enumerated powers, and they include a substantial list of authorities that influence both domestic and international policy.
Under Article I, Section 8, Congress is given the power to enact legislation that is "necessary and proper" for executing these granted powers, thereby also creating a space for implied powers. Implied powers are not directly stated in the Constitution but are derived from the enumerated powers to ensure the government can operate effectively. Inherent powers, another type of power, are assumed to exist since they are essential for a sovereign nation though they are not explicitly mentioned in the Constitution.
The significant powers of Congress range from the authority to tax, maintain military forces, and regulate trade to declaring war and establishing laws on naturalization and bankruptcy. These powers provide Congress with a pivotal role in guiding the national government, vastly extending its influence beyond what was possible under the Articles of Confederation.