I just discovered that the 56 Victoria I recently purchased is not in Park when the gear shift selector is in Park. I have the car jacked up-back wheels are off the ground. I was checking on the brakes. The wheels turn easily when the car is in Park. Might this be an adjustment issue? Thanks.

Could be the parking pawl.

OOPs, I don't know what that is. HELP

Does the ‘Park’ work with both rear wheels on the ground?  If it does, then with both rear wheels off of the ground and in park, one or both of the rear wheels will typically turn depending upon the type of differential is in the vehicle.  The wheel opposite of the wheel you are turning will be rotating the opposite direction indicating an open or single track rear end.  If the transmission is in neutral (or the parking pawl is not engaged in the park position) and both tires rotate the same direction, you likely have a posi-track differential.

Lorena, Texas (South of Waco)