The influential document that outlines the foundational principles of the U.S. justice system is the United States Constitution, particularly its amendments. The Bill of Rights, ratified in 1791, comprises the first ten amendments and guarantees essential civil liberties such as freedom of speech, religion, and the press, and rights related to criminal proceedings. The Constitution provides the framework for the judiciary, establishing the rule of law and the separation of powers among branches of government. These principles laid the groundwork for a legal system that upholds individual rights, due process, and equal protection under the law.