The United States Federal Government is divided into the legislative, executive, and judicial wings, comprising Congress, the President, and federal courts respectively. However, the balance of power is slightly tilted in favor of Congress, as it has the sole power to make laws that apply throughout the country, with the President in second place, as he alone can enforce these laws. The US Constitution is a type of contract that was ratified by individual states after the Great War of Independence. This document aimed to create a federal government; it had nothing to do with individual states, who had their own constitutions. Then, how did these states agree to set up a federal government with such a skewed distribution of power? And how could they be rest assured that this government wouldn't try to enforce its will upon them? The answer lies in a concept called 'enumerated powers', which is explained in the following sections. Enumerated powers are those specifically given by the Constitution to the federal government. It is not allowed to perform any role other than what is specified in these powers. Most of the enumerated powers of Congress occur in Article I, Section 8 of the Constitution, from Clause 1 to 17, while those of the President occur in both, Article I and II, with a majority in the latter. The need for these powers arises in the fact that, when the newly-independent American states met to ratify the Constitution, they were apprehensive about an exceedingly powerful federal government, like that of the previous British administration. Therefore, the Framers of the Constitution took care to strictly specify the powers of the new federal government, to ensure that it did not impinge on the states. Later, they even added the Ninth Amendment, which specified that the federal government should restrict itself only to the enumerated powers, and nothing else. There are two schools of thought regarding how these powers should be interpreted. The 'strict constructionists' argue that Section 8 should be taken literally, which means that, Congress has no power other than those enumerated in the Constitution. On the other hand, liberals, or 'loose constructionists', support a broader interpretation of Section 8, saying that Congress needs other powers to effectively perform those enumerated (specified). The liberals cite individual clauses in the enumerated list, such as the Commerce Clause (allowing Congressional regulation of interstate trade) and the Elastic Clause (allowing Congress to pass any laws necessary to carry out its enumerated powers), as proof that the Framers wanted Congress to have more liberty. While the original intention of the Framers was to restrict the federal government to the enumerated list of powers, a few amendments to the Constitution expanded the powers of Congress even further. For instance, the Sixteenth Amendment, passed in 1909, allowed Congress to collect income tax, and the Eighteenth Amendment, passed in 1917, gave it the power to prohibit alcohol (canceled in 1933).

• To levy and collect taxes for the defense of the country and matters of general interest.
• The duty of governing trade with foreign nations, between different states ('Commerce Clause'), and those with Native American tribes.
• The power to take out loans on the credit of the United States.
• Coining a currency, regulating its value, and standardizing weights and measures.
• To decide rules for punishment for counterfeiters of currency.
• It decides the rules for naturalization of immigrants, and those for declaring bankruptcy.
• To establish an army and navy for the country's defense.
• Setting rules for the governing and conduct of the armed and naval forces.
• The power to declare war, issue 'Letters of Marque', and decide the rules for capture of territory.
• To establish a system of post offices and connecting roads.
• Establishing a system of patents and copyrights, to promote advances in sciences and arts.
• To establish a militia (armed citizens' group), to fight invaders, quell uprisings, and ensure the implementation of laws.
• To decide rules for the militia's armament and training, while its composition will be decided by the states.
• The exclusive right to govern any territory that hosts the nation's capital, and those on which federal forts, armories, dockyards, and other establishments have been built.
• It decides the rules for prosecution of those violating maritime laws, and the 'Law of Nations'.
• To establish federal courts at a subordinate level to the Supreme Court.
• Authority to pass any laws which may be 'necessary and proper' to perform the above functions ('Elastic Clause').

• The executive power to decide the fate of a bill passed by Congress, based on whether it is constitutional or not.
• Appointment of ambassadors, judges, and other federal officials, in consultation with the senate.
• The power to grant pardon to a person convicted of a crime against the United States (federal offenders).
• Serves as the Commander-in-chief of the armed forces in times of war.
• To receive ambassadors and public dignitaries of foreign countries.
• To carry out 'recess appointments' of officials who hold office until the next session of Congress.
• Can call for sessions of both houses of Congress in certain situations.
• To sign treaties, and demand written opinions about the functioning of executive departments from their Principal Officers.
• The duty to ensure that the Constitution of the United States is upheld at all times.

One might think that, strictly specifying the federal government's power might be enough to keep it in check. However, the Framers of the Constitution went a step further to empower the states, by enacting the Tenth Amendment. This Amendment grants reserved powers to the states, which are those powers that the Constitution doesn't give the federal government, but doesn't forbid the states from having either.