This is pretty cool.
EEOC briefs are now on line. [Here]
They cover briefs filed in the US Circuit Courts of Appeals in which the EEOC was a party, plus amicus briefs filed in the US Circuit Courts of Appeals, District Courts, and state courts.
And there is a user-friendly search function.
Briefs filed in the US Supreme Court are not in this collection, and can be found through the US Solicitor General's collection [here].