bringing money to the states is a very big hassle unless you are US citizen. as a citizen of the US you can open bank account in $ with showing proof of legitimate source of income in $. the limit to carry cash per person is 10k so probably one would have to send it through bank transfer or "hundi" system-which is not so reliable especially with 50k.

i am pretty sure that in case of a GC holder, it would be almost impoossible to bring 50k without the option of bank transfer or hundi.