Since this is a photography site, I have a portrait to show ...

Sante Patate wrote:

What? It is called the Copyright Act - s106 in the US Act is the relevant one. You can find the text at http://www.copyright.gov/title17/.

If you have just got the idea that a photograph of a sculpture would not breach the copyright in the sculpture, you are wrong (the photograph is a "derivative work"). You might want to read Rogers v Koons (1990) as well. There really is no question that, absent permission, the OP has infringed the sculptor's copyright.