The Public Domain Is the Rule, Copyright Is the Exception

"Most of our culture, knowledge, and history isn’t "owned" by anyone at all—it is available for all to use in the vibrant and ever-expanding public domain. This domain is populated by formerly copyrighted material and material that was never copyrightable in the first place. The first category is what most people probably think about when then they think of the public domain: things such as literature, art, music and movies, for which the copyright term has expired or the rightsholder has dedicated the work to the public domain. Under the original U.S. copyright law, each generation was largely free to use the copyrighted material of previous generations, because terms were much shorter (and so was the scope of what could be copyrighted). But terms grew longer and longer until, one year ago, material from 1923 onward finally started entering the public domain each year.  There doesn’t seem to be much appetite to extend U.S. terms further (not so other countries), so presumably these kinds of works will continue to enrich the U.S. public domain...."