Friends Thanks again! Here is the letter to Senator that I wrote. If you like it you can change relevant information and rewrite. To be honest I have no clue whether writing such a letter helped at all. But what's there to lose?
Honorable Dear Senator XXXX,
I am writing to seek your help on a personal important matter. Since [485 receipt date] I am waiting for my own and my wife's Green Card cases with USCIS to be approved. Our dates are current now. If your office could help expedite the processing of our cases, we would be extremely thankful to you. The case numbers are:
xxxxxxxxxx - [applicant name]
xxxxxxxxxx - [applicant name]
We have been in this country for about XX years now. Had XX wonderful children here. I work for XXXXX in XXXX as a XXXXX.
Not having a Green Card has hindered our plans to purchase a home and start a business among other things. We have been good members of the society with good education, and track record of community service and other contributions to good causes. We would be very excited to become permanent residents.
I really appreciate your kind attention and would like to profoundly thank you in advance for your help.
Please accept our sincere thanks & best wishes for your service and dedication to the community as well.
Warm Regards,
XXXX & XXXXX
[City, State]
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p.s. - in response to somebody asked .... yes our children were born here. So fortunately we never had to worry about kids' visa etc. Got their PIOs ASAP so that India was easy. But its weird that they couldn't get Indian Citizenship which I strongly want them to have. However some weird government rules are prohibiting that.