Fight Discrimination
Discrimination against non-theists happens all the time in one form or another. If it happens in the workplace, it can be especially tough. Do what you can to try to document it and you may be able to seek remedy with the U.S. Equal Employment Opportunity Commission by filing a complaint. Read their website to learn what kinds of practices are prohibited. A brief overview of the law specifically addressing religious discrimination is available here.
The same kind of intolerance happens in the publics schools perpetrated by teachers, officials and students. The U.S. Department of Education's Office of Civil Rights (OCR) exists to protect children within the country's educational systems from discriminatory practices. For advice and support before filing with the government, contact The Public School Parent's Network.
Even in the courts and other government offices we sometimes face being treated as second class citizens. Atheists, or those accused of holding atheistic beliefs, may be subject to discrimination and persecution in some Islamic countries. According to popular interpretations of Islam, Muslims are not free to change religion or become an atheist: denying Islam and thus becoming an apostate is traditionally punished by death in men and by life imprisonment in women, though in only three Islamic countries is apostasy currently subject to capital punishment. The situation is less dire in the U.S. but still is experienced from all branches of government from local courts to the military.
If you have a personal story to tell about being discriminated against for lack of religion, please write it down and collect any evidence available. The Freethought Society of Greater Philadelphia's Anti-Discrimination Support Network (ADSN) is collecting narratives highlighting instances of bigotry against the nontheist community. To make a report of discrimination, use their report form.