You're being underpaid because you are Indian. Unless you have a PhD and/or some stellar credentials from undergrad (Top 10 EE doesn't mean shit), you're SOL.
You can never prove racial discrimination in these types of cases and especially when you're Indian - the highest income earners and most educated group in the US. Most people in the tech industry hold totally unfair stereotypes against Asians, and especially Indians. They think that you can work for 1/4 of their pay for the same level of work. This is why there is such a huge hullabaloo about H1-B Visas.
There was an article in the San Jose Mercury a couple of days ago regarding how Asians now make up the majority of tech workers in Silicon Valley (~ 51%)! Half the article was about this sociologist professor and some "activist" in Oakland who complain that "companies don't want to hire 'Americans'."

They don't realize the work ethic and quality of work by Asians is second to none but they also have the temerity to think that Asians will work for less pay.
You need to diversify your options. As an EE, you're somewhat stuck in a rut working for large corporations where you're nothing more than a cog in the wheel. To move up in those situations, politics and other things matter a lot. If you can branch out and get into management or even software or software cum hardware, you will be able to command much better remuneration than what you've stated.
Btw, are you in the Silicon Valley? $70K/yr. for an EE (with a Master's Degree?) is quite lean. If you're in the midwest or some other armpit of America, then it is manageable.