Short answers, pulled from the story.
On the 1st of March 1781, the Articles of Confederation officially became the first constitution of the United States. This document gave little power to the central government while leaving most authority with individual states.
Delegates signed the original United States Constitution on the 17th of September 1787. The document was submitted to Congress three days later and eventually ratified by nine states by the 21st of June 1788.
The United States Constitution has twenty-seven amendments structurally. The original text prior to these amendments remains untouched since precedent set 1789 Congress considered proposed first several Constitutional amendments.
Marbury v Madison 1803 Chief Justice John Marshall established the principle of judicial review allowing courts declare laws unconstitutional if they conflict with the Constitution. This decision solidified the Supreme Court's role as final interpreter of constitutional meaning.
Eighteenth-century Enlightenment philosophers Montesquieu John Locke Edward Coke William Blackstone James Madison Benjamin Franklin Thomas Jefferson and David Hume greatly influenced the framers. These thinkers provided ideas regarding separation powers consent governed and natural rights that shaped the Constitution.