Some location shooting was done in Castle Williams on Governors Island, NYC harbor. The special effects were applied to the modern plumbing and fixtures to make it look like the Civil War era. Torches were attached to the curved walls and boxes constructed over the pipes then plastered to match the walls. Wooden boards were attached to the iron bars of the window. Richard Basehart running shoes were covered with rags to look like he was only wearing rags on his feet. They built a curved track inside the jail to accomplish a long tracking shot as he was brought to his cell. At one point he goes to the wooden boarded window and looks out. Later they had constructed a hangman's scaffold on a hill, with extras working on it, near Fort Jay and set up the film camera at lower angle with a frame in front of it that looked like the wooden framed window the character looks out of to see the scaffold.