Fortunately, federal and state laws provide workers with some protection from the abusive practices of employers. There are laws governing termination, harassment, time off, benefits, safety, and other things.
Employers do their best to prevent you from benefiting from the rights that the government has provided. They will even trick you into signing away your rights by hiding limitation periods in their handbooks. If you do not file your lawsuit by the date specified in the handbook, you cannot file it at all.
If you believe that your employer has taken advantage of you, it is important to assert your rights as soon as possible.