Added a few companies to my list of quality, made in the USA products (Dirtball & Wickers), thanks
For those who may be interested, with the exception of the two above and TAD, almost every pair of pants listed in this thread is made in China, Vietnam, Cambodia, Malaysia, Afghanistan, etc. This is true for some brands costing hundreds of dollars (ArcTeryx)
SOME items from Filson, Cabela's and Carhart MAY be made in the US still, but they are few and far between. I would much prefer to spend $200 - $300 on a pair of quality pants, not made in SE Asia and have them last 10-15 years, than to buy something for $20 - $40 and toss it in the land fill when it tears up in a few months. If more people INVESTED in gear and clothing instead of buying "price", there would not be so many items being made in China, Cambodia, etc.
This is especially true for companies like North Face, Patagonia and Marmot, who have "expedition to Everest" written all over them, charge a zillion dollars for their garments and make them all in SE Asia. It IS difficult to find quality brands made in the US still, but it can be done. I have dozens of pages of notes and links for such products and these are the companies that we should be supporting, with our hard earned cash, so we can go enjoy the great outdoors.
EDIT: To end on a more positive note, I though I would add a few items from my notes that may fit the criteria specified by the OP. Check out L.C. King in Tennessee,
http://www.dubarry.us/ - has several stocking dealers throughout the US and
http://www.oakhall.com/mens/ - carries well made men's clothing from around the world.
Cheers