The correct answer is the Lilly Ledbetter Fair Pay Act in 2009
Basically, the law was such that you had a restricted amount of time to report your employer if they didn't have fair payment towards all. However, since it was almost impossible to find out that you weren't paid equally as others before the deadline passed, people couldn't ask the help of courts. The fair pay act removed the deadline and made it possible to sue whenever you find out.
