What would cause my truck's wheel's to lock up?

I was driving and all of a sudden the wheels locked up. I was able to drive it off to the side of the road, but not easily. It feels as though somebody is putting a foot on the brakes as I drive. In nuetral the truck won't roll. I pulled the front wheels and they both spin. I pulled the back wheels and they move from 12 to 2 and back again (not completely locked). Like I said it can move but not enough to drive. It's stuck on the side of the road and I don't know what to do. I give it gas and it revs up then lurches forward. It is a 1993 Ford F150. Any ideas on how to get it home?