The U. S. Constitution is the central instrument of government and the 'supreme law of the land'. It is the oldest written Constitution in the world that is in force. It was written in 1787 in Philadelphia by the Continental Congress of the new American republic and was officially adopted in 1789.
The objective of the writers was to outline the structure of a new, strong central government after the years of weakness and chaos resulting from the preexisting 'Articles of Confederation and Perpetual Union' which loosely bound the colonies together since 1778. The Constitution outlines the structure and powers of the 3 branches of government (executive, legislative, judicial) and the 3 levels of government (federal, state, local). The basic principles of the Constitution are the same today as when it was written: 1 -- the 3 branches of government (executive, legislative, judicial) are separate and each is checked and balanced off by the power of the other two, 2 -- the Constitution is supreme, 3-all persons are equal before the law, as are all states and each state must be democratic and respect the law of others, 4 -- the people can change the Constitution by the methods outlined within it. Amendment of the Constitution may be initiated by a 2/3 vote in each chamber of congress, or 2/3 of the states calling for a national convention.
In either case a vote of 3/4 of the states is required to actually make an amendment. The interpretation of the Constitution has changed over time without amendment by various pieces of legislation and judicial decisions. The Constitution has had 27 amendments. The Bill of Rights, the first 10 amendments to the Constitution, were adopted in 1791 in order to meet demands for the signature of Massachusetts and other states to the Constitution: BILL OF RIGHTS (THE FIRST 10 AMENDMENTS TO THE CONSTITUTION) 1-freedom of worship, speech, press, right of peaceful assembly, right to petition the government 2-right of citizens to bear arms 3-troops may not be quartered in private homes without owner's consent 4-guards against unreasonable searches, arrests, seizures of property 5-requires indictment by a grand jury for major crimes before trial, prohibits repeated trials for the same offense, forbids punishment without process & that you don't have to testify against yourself 6-guarantees a speedy public trial for criminal offenses, trial by an unbiased jury, legal counsel for the accused, and that witnesses must attend the trial in the presence of the accused 7-guarantees trial by jury in civil cases in anything valued at more than 20 US dollars 8-forbids excessive bail or fines and cruel or unusual punishment 9-people have other rights than those mentioned in the Constitution 10-powers not delegated to the federal government belong to the states or the people.