I had the same symptoms with my '64 when I bought it last year.
If the window is all the way up, you might be able to get lucky and just have a buddy push down (HARD) on the top of the window while you hit the switch, sometimes the motor and mechanism just need a jump start.
More than likely though, it is one of two things. The regulator is all boogered up or the motor is shot. In my case, it was both.
First things first, take off the door panel to get to the bolts that hold the regulator in. It's not hard to work on, really. Take out the regulator and motor (it's in one piece at this point). I would clean and lube everything in the regulator gear housing and the scissors lift. While you're at it, you should hook up the motor to the battery direct and see if it spins. NOTE! Just because it spins under power doesn't mean it has enough juice to raise and lower your window.
If you need a new motor: Don't waste your time and money with the used junk they're selling on Ebay, just buy a new motor. I bought mine from Thunderbird Headquarters, as they seemed a little cheaper at the time than everybody else ($125 plus core). However, there has been a link on
www.lcoc.org/bb.htm posted very recently to a shop out of florida that might have T-bird motors new for as little as $75.00 with no core. It's worth a few minutes to check it out.
Getting the motor/regulator/scissors assembly back in the door and hooked to the window is the FUN part. Good luck.
In all reality, I'd say your motor is shot. Sorry.