”As the authors of the [United States] Constitution knew, copyright was created in Great Britain by the Statute of Anne in 1710 for the purpose of curbing the monopolistic practices of the London Stationers' Company and also, as its title proclaimed, "for the encouragement of learning." At that time, Parliament set the length of copyright at fourteen years, renewable only once. The Stationers attempted to defend their monopoly of publishing and the book trade by arguing for perpetual copyright in a long series of court cases. But they lost in the definitive ruling of Donaldson v. Becket in 1774.
”When the Americans gathered to draft a constitution thirteen years later, they generally favored the view that had predominated in Britain. Twenty-eight years seemed long enough to protect the interests of authors and publishers. Beyond that limit, the interest of the public should prevail. In 1790, the first copyright act—also dedicated to "the encouragement of learning"—followed British practice by adopting a limit of fourteen years renewable for another fourteen.
”How long does copyright extend today? According to the Sonny Bono Copyright Term Extension Act of 1998 (also known as "the Mickey Mouse Protection Act," because Mickey was about to fall into the public domain), it lasts as long as the life of the author plus seventy years. In practice, that normally would mean more than a century. Most books published in the twentieth century have not yet entered the public domain. When it comes to digitization, access to our cultural heritage generally ends on January 1, 1923, the date from which great numbers of books are subject to copyright laws. It will remain there—unless private interests take over the digitizing, package it for consumers, tie the packages up by means of legal deals, and sell them for the profit of the shareholders. As things stand now, for example, Sinclair Lewis's Babbitt, published in 1922, is in the public domain, whereas Lewis's Elmer Gantry, published in 1927, will not enter the public domain until 2022.“
[The above three paragraphs are from the article "Google & the Future of Books", Robert Darnton, The New York Review of Books, Volume 56, Number 2, February 12, 2009]