Congressional Chronicle -- A resource for House and Senate floor proceedings. Access the legislative schedule, a directory of committees and members, bills, votes and statistics about each session of Congress.
Yes, I know this is a Wikipedia article, but I think you will understand why I selected it. It includes a well-organized, comprehensive synopsis of ISIL (as Obama references them) or ISIS (as US media names them).
YOU MUST READ the preface, which is located above the "Contents" box.