In Article I, Section 6, Congress is authorized to:
“To promote the Progress of Science and useful Arts, by securing for limited Times to Authors and Inventors the exclusive Right to their respective Writings and Discoveries.”
Somehow, I don’t think the Founders envisioned century-old works, whose authors are long dead, being covered.
Well, they probably believed they were living in a finite universe, and a “limited time” could thus easily be construed to mean, “until time stops.”
If I had the power to change the law it would be a 21 year patent for an original invention, 14 years for an original work of art or literature and 7 years for a song recording or film/TV show.
AND NO SOFTWARE PATENTS!