Here's the US Constitution (Article 1, Section 8) on copyrights and patents:
Pay special attention to the part about "for limited Times." Despite the "right" in the name "copyright," copyrights and patents aren't rights the way freedom of speech, or even owning a houise and the land underneath it, are rights. In the case of homes, an owner can pass the right of ownership on to her children, grandchildren, and so on forever. But copyrights and patents are in force only for a limited time.
Over the past 50 years or so, Congress has repeatedly extended the duration of copyrights. Critics note that these extensions have come just as the first Mickey Mouse cartoon was about to pass out of copyright. Although all concerned say this is a coincidence, the Disney company has become a sort of poster child for people who don't like copyrights. Ironically, many of the Disney cartoons (Snow White, Cinderella, etc.) are based on stories that are in the public domain (okay for anyone to use), but would still be under copyright if today's copyright law had been in effect when earlier versions were written.
Why did the writers of the Constitution include provisions for copyrights and patents? What they had in mind was not an absolute property right, but rather a bargain in which society lets authors and inventors make a lot of money from their ideas, but in return those ideas must eventually belong to the entire society, free for anyone to use. (In particular, a patent application must explain how to make the invention, with enough detail so that any competent engineer in the field of the invention (a mechanical engineer, an electrical engineer, or whatever specialty is relevant) could duplicate the invention after reading the patent.)
Protecting the openness of ideas is particularly important for patents. Before there were patents on inventions, inventors used secrecy to protect their ideas, and so the knowledge of how to use the invention often disappeared after the inventor's death. This has happened repeatedly throughout history; an interesting example is that several colors of paint were unavailable for long periods of time until they were reinvented. But the most famous example is Antonio Stradivari (1644-1737), an Italian violin maker generally considered to have been the greatest maker of string instruments of all time. Nobody in modern times has been able to create comparable instruments, according to violinists, although blind listening tests seem to show that the musicians can't really tell the difference between a "Strad" and another high-quality violin. Stravivari never published his techniques, but perhaps he would have in return for patent protection, if that had existed in his time. (Today you can buy one of the 500 or so Strads still in existence for about $2 million to $3 million.)
But it's important for copyrights, too. Have you ever been at a birthday party at a restaurant? It's very common that when they bring out the birthday cake, all the waiters gather around the table and sing "Happy Birthday." But until quite recently they did so illegally; there is a copyright currently owned by Warner/Chappell Music, based on the original authorship of a song with the same melody but different lyrics by sisters Patty and Mildred Hill in 1893 (more than a century ago). A 2015 court decision has invalidated the copyright, but may be appealed by Warner, which had been collecting about $2 million per year in fees charged for permission to use the song, especially in films.