In regards to where the cotton comes from... this page from Wikipedia is interesting (look about halfway down the page, to where there's a world map).
http://en.wikipedia.org/wiki/Cotton
Apparently the US is the worlds largest EXPORTER of cotton. China is actually the world's largest PRODUCER.
I don't think that there's much left in the US in terms of cotton gins and weaving equipment. So yes, it's not "green"... the cotton is grown here but shipped abroad for combing, spinning, weaving, and finishing.