The full text of the Bill of Rights, including its preamble, is available on the website of the National Archives and Records Administration. The 10 amendments are also accessible on the Bill of Rights Institute website, which provides visitors with the opportunity to download the text in PDF format.
The National Archives website also lists the original 12 amendments, of which state legislatures ratified 10, and offers information on why the states wanted the Constitution amended. Additionally, visitors to this website can find information about the Declaration of Independence and the Constitution and its amendments throughout the years. The Bill of Rights Institute website, among other things, expands on the principles on which the Constitution is based, such as the separation of powers and the rule of law.