[Alibi]

Drum brakes or disc? I would assume drum...

The first thingthat came to my mind was that your rear bearing had siezed, but you said you tried it again and it rolled fine....so then that leads me to think of your braking system.

It takes quite a bit of force to keep a tire from moving at all. If you have drum brakes, remove the tire and pull the drum off the shoes. Inspect the springs to see if any have broken, causing a pad to rub against the drum (and therefore keeping it from moving). If that checks out good then the next thing I would look at would be your proportioning valves (long brass-colored things on the master cylander...not sure on an ABS car tho). Could just be gummed up or ??

If those are't the culprit....hmm....not sure. Maybe something with the ABS? Or the brake booser?