Every section includes links to important cases and additional information from the Legal Information Institute’s online treatise Wex. Also links to LII’s version of the Constitution Annotated, which is in text form.
“The Constitution of the United States of America: Analysis and Interpretation (popularly known as the Constitution Annotated) contains legal analysis and interpretation of the United States Constitution, based primarily on Supreme Court case law.” This site has PDFs for each section of the work.
Here you can find the status of current bills, as well as information about previous bills and legislation. For older materials, the full text is not always available, but some information about the actions taken on bills may be found.