Suddenly, after years of doing without any decent free source of federal appellate decisions, legal researchers now have least two excellent options:
Both the Public Library of Law and Justia have federal circuit court cases going back to 1950. Their search engines are user-friendly, and each allows you to limit your search to a particular circuit.
(The Public Library of Law and Justia (via its Supreme Court Center) also have all Supreme Court decisions. In addition, Justia has federal district court opinions from 2004 to the present, and the Public Library of Law has state appellate and high court cases from 1997 to the present.)
Why so much new federal case law all of a sudden? As Robert Ambrogi explains it, in mid-February public.resource.org and the Creative Commons jointly released 18 million pages of public domain federal case law. After that, it was just a matter of days before Justia and the Public Library of Law took this raw data and rolled out search engines for the decisions.