The main purpose of the U.S. Constitution is to establish the basic rights of all American citizens and provide direction on how the government should work. The Constitution also provides the framework for law and order and describes the roles of the government's federal judiciary branch, legislative branch and executive branch.
The Constitution officially took effect on Sept. 17, 1787, during the Philadelphia Convention and has been amended 27 times since its adoption. The first 10 amendments of the Constitution are known as the Bill of Rights.
The U.S. Constitution consists of a preamble, seven original articles and 27 amendments. The first three articles of the Constitution define the role of the president as the head of the government, the Supreme Court as the administrator of the judicial branch and the role of the bicameral Congress within the legislative branch of the government.
The Constitution and its amendments define civil liberties, such as freedom of religion, freedom of speech, freedom to assemble and the freedom to petition, which are rights that citizens continue to enjoy. The Constitution also provides citizens the right to possess firearms, the right to a public trial for criminal offenses, the right to question unusual punishment and the right to question property seizures and arrests without a warrant.