'56 T-Bird rear spring removal

[modelamike65]

My problem is removal of the front bolt that secures the rear spring. I have released the rear shackle connections and released the spring from the rear axle and removed the nut from the front bolt that holds the spring. So there is no pressure anywhere along the spring. I am unable to even turn the front bolt that goes through the frame, the spring bushing and spring bracket. Has that bolt been pressed in place to cause this problem? When I pound on the end of the bolt with a punch and hammer, it sounds and feels like it is part of the frame.