Article II of the Constitution defines the powers of the executive branch by establishing a President of the United States of America. Section 1 of Article II begins:

The executive Power shall be vested in a President of the United States of America. He shall hold his Office during the Term of four Years, and, together with the Vice President, chosen for the same Term, be elected[.]

At the time the Constitution was written, most countries in Europe still had monarchies, so a country having a president with a limited term of office was a radically new idea. But the limited term was done, in part, as a reaction to the monarchies of Europe, where one person held total power for an indefinite amount of time. The delegates to the Convention were afraid of placing too much power in the hands of one person. In the end, they created the executive branch with a system of checks and balances included into the Constitution, and our current system of a single President was born.

Article II of the Constitution grants the President a number of powers. He or she is the Commander in Chief of the United States Armed Forces, makes treaties (although they have to be approved by Congress), and can grant pardons for offences against the United States, except impeachment. The President appoints Ambassadors and Supreme Court justices, too. Article II establishes all the responsibilities of the President as well. For instance, the President has to periodically give Congress information on the State of the Union and make sure the laws are faithfully executed, among other responsibilities.

The Vice President, department heads called Cabinet members, and heads of executive agencies help the President lead the country. Unlike the powers of the President, though, their responsibilities are not defined in the Constitution, except that the Vice President succeeds the President in case of death or disability.