Seeing a black panther isn't like sasquatch... there are definitely wild black panther in the US, they just aren't concentrated and there arent many.
Just as people may not believe that mountain lion arent in the south, thereis a concentrated population of mountain lion in florida. There are records of mountain lion being harvested in Mississippi, Louisiana, and many other states. Contact the National Audubon Society if you don't believe there are cougars and black panthers spread out over the US. They'll tell you there are.