seized?

1986 f250 351 w. had starter problem for a while.starter wouldnt turn unless i hit it with a hammer so i put in a new starter and works but wont turn engine.
i took starter off and turned the key and starter turned.I tried to turn engine by hand and wouldnt turn.could it be the flywheel or is the engine seized?had truck parked for a week.hit starter with hammer and starter turned engine,bought new one and installed it and wont turn motor.
HELP!!!!!!!!!!!!

Well, first I'd make sure the battery was fully charged. Then I'd check all the power connections/cables/wiring to make sure it was clean, secure, and not damaged. If all of that is OK, my next question is did you do anything else to it besides the starter replacement?

Well, first I'd make sure the battery was fully charged. Then I'd check all the power connections/cables/wiring to make sure it was clean, secure, and not damaged. If all of that is OK, my next question is did you do anything else to it besides the starter replacement?
all i did was change the starter.someone told me the engine froze.is that possible?

Pull the spark plugs & see if it turns over.

Pull the spark plugs & see if it turns over.
i dont know if it was frozen or not but today was in the 40's and it fired right up.