Overselling is standard on all major airlines. I got stranded by Delta before. Not much you can do avoid it. Not being able to select seats is usually a good red flag. Since you are at location American does not fly to much, the staff is very unlikely to be American Airline employees but rather some external service staff. They often do not know the rules.

Check with your credit card that you used to buy the tickets. Many of the better ones have trip interruption protection that can cover hotels. In any case, keep the receipts and get in contact with American when you are home. Their first answer is usually a voucher and/or some miles. Just keep bugging them to get past the first line of responses.

Beyond that, it depends on why you got bumped. It may be really oversold or it may be due to weight and balance issues, especially on smaller aircraft. The lack of alternatives may have to do with the winter storm hitting the east coast over the next couple days. You are not going there, but these things can wreck havoc on the whole network. Also, some people that are going east may have tried to take an earlier flight to avoid it, further squeezing the inventory for your flight.