Having established themselves as one independent state, the United States of America turned to creating a government system. Their first idea - the Articles of Confederacy - failed miserably but the second attempt, though it took some effort, was much more successful and resulted in the foundation of the US Constitution. Wanting to break free from what they saw as a corrupt Europe, they came up with a system which had begun in ancient Greece and continued by England and France, but would be taken further by them. The system, sometimes called the separation of powers, meant that the country would be controlled by a number of bodies who would have balanced power and would be able to take steps to keep in check any of the bodies that tried to take too much power; therefore, it became known as the system of checks and balances.
Proposed to them by philosopher Baron de Montesquieu, the idea was taken on board by the founding fathers of the US in their commitment to remove any possibility of tyranny from taking hold their new country. Seeing how democracy had been furthered in the UK Parliament, which Montesquieu was rather enamoured of, by distributing the power between two branches, a system was put into place with three branches: executive, legislative and judicial.
Montesquieu had lived in France during the age of enlightenment and died in 1755. He saw two power in two bodies - the sovereign and the administrative; the latter was formed by the three branches mentioned previously. Though he was most fond of the idea of a monarch upholding a constitution, as was the case in Britain, he believed that government should be divided so that each power should have some degree of power over the other. Having fought for a republic, the US did wish to have a monarch but nevertheless, the idea of separating power into three branches, all having power over each other made a lot of sense. In fact, the idea seemed so nifty that many states in the Union emulated it for their state governments, though different titles apply: for example, a Governor instead of a President. The idea of power distribution can even be seen by the way that there are both state and federal governments.
The Legislative Branch
The United States Congress, comprising the Senate (the higher house) and the House of Representatives (the lower house) makes up this branch. It is responsible for drafting, debating and ratifying legislation and cannot pass this duty on to any others. The House is made up of 435 members serving two-year terms, each representing a congressional district and therefore proportionate to the size and population of the states they represent. The Senate, on the other hand, contains only 100 members who have terms of six years - there are two members for each state. Having two houses allows them both to check and balance the other. This came about because large states wanted proportional representation, because they would get more of a say, and small states wanted equal representation, so as not to be ignored, thus a compromise of both was selected. Owing to this, the public1 can check, and be checked, by the scholars2, though the members of each house aren't necessarily popular or scholarly; the two have powers to rival the other.
The Executive Branch
The President of the United States of America is, essentially, this branch but it also includes the government's cabinet and independent government agencies. It is his duty to 'take care that the laws be faithfully executed'3 and thus he does not need to actively enforce laws, but subordinate members of this branch have to. The President and Vice-President4 serve four-year terms and they are voted in by the electoral college. The President can, as of 1951, serve only two terms, except for in the case where they have taken office as a replacement for the current President5 in which case they can serve a maximum of ten years. This followed Franklin Delano Roosevelt's tenure which he began in 1932 and would have lasted 16 years had it not been for his death in 1945.
The Judicial Branch
The Supreme Court of the United States and lower courts form the final branch of the checks and balances system. The Supreme Court is the highest court in the US and is therefore in charge of upholding laws and interpreting them. The Supreme Court, for the most part, deals only with high profile cases meaning most of the law interpretations appear at the Appellate6 level. The nine members7 of the Supreme Court are appointed by the President and hold that position until they die, are impeached or retire. This branch's duty is to interpret laws in order to determine if they are constitutional or not when put in practice; they also make sure that the decisions of lower courts abide by the constitution.
Power of Veto
The idea of having these three branches is not so that the power is completely separated, but so that each branch has the power to restrain the other two from abusing their powers, and to this end, each branch has certain powers of veto over others. Congress has to approve the President's nominations and also controls the budget, as well as military-related appointments and the army's code of conduct despite the President being Commander-in-Chief. The President can veto Congress's laws, but if Congress holds a two-thirds majority it can override the veto. The Supreme Court, though, can declare this law, or a law supported by both other branches, unconstitutional and therefore illegal once it has been put into practice. However, Congress has the power to impeach a Supreme Court Justice as well as the President. As well as being able to impeach the President, both houses can hold a Congressional Oversight to ensure members of the Executive Branch are upholding their duties; these can either be investigated by an individual house or the whole of Congress.