Gary --
I agree with Bloo, but I'd like to be more specific. Since you car has been sitting for so long, it is very likely that the Bendix drive on the starter has rusted up a bit and is not free to engage the flywheel when the starter spins up. The fix is easy and cheap. Just disconnect the battery (to avoid ugly shorts and sparks), then remove the battery cable from the starter. Next, back out the two bolts attaching the starter to the flywheel housing and remove the starter from the car. Then, spray some WD-40 or PB Blaster on the threads of the Bendix, tap it a few times with a hammer and a screwdriver, run it back and forth a couple of times and reinstall. I'd bet money that will solve the problem. Hope that helps.
All the Best, Chip