The USA is a presidential republic. The legislative power of the USA is vested in the Congress of the USA. The Congress was created by Article I of the Constitution, adopted in 1787. It consists of two chambers — the Senate and the House of Representatives. The Senate is made up of 100 members (2 from each state) elected for a term of 4 years. One third of the Senate is elected every 2 years. To be elected a Senator, a person must be at least 30 years old, and have been a citizen of the USA for at least 9 years. The House of Representatives comprises representatives from each state, elected for a two-year term. The number of representatives from each state depends on its population, but each state is represented. To be elected a representative, a person must be at least 25 years old, and have been a citizen of the USA for at least 7 years. The presiding officer of the Senate is the Vice-President of the USA. The presiding officer of the House of Representatives, the Speaker, is elected by the House. The work of preparing and considering laws is done by the committees of both Houses. There are 15 standing commissions in the Senate and 19 in the House of Representatives. The Congress assembles at least once a year.The executive branch of the government consists of the President, the Vice-President and the Cabinet. The President's term of office is four years, together with the Vice-President, elected for the same term. The President is the head of the executive branch of the government; he appoints the members of the Cabinet. The Cabinet advises the President on many matters and is composed of the heads often executive departments; Secretary of State, Secretary of Treasury, Secretary of Defense and others.The judicial branch of the government is headed by the Supreme Court which settles disputes between the states. The Supreme Court may veto any law passed by the Congress if it contradicts the Constitution of the USA. The USA is a federal union, and the President is the head of the federal government, which deals with international problems and national matters. But every state has its own constitution and state government headed by the congress and managing their local affairs. Their laws and decisions must not contradict the Constitution of the USA. The US national flag — stars and stripes — is red, white and blue. Thirteen stripes represent the original 13 states the 50 stars represent the current number of states in the USA.